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PLATE  1.    A  MAN-MADE  PARADISE  Ol{  A  MAN-MADE  DP:.SKKT.    WIllCHr 


CIVIC  BIOLOGY 

A  TEXTBOOK  OF  PROBLEMS,  LOCAL  AND 

NATIONAL,  THAT  CAN  BE  SOLVED 

ONLY  BY  CIVIC  COOPERATION 


BY 

CLIFTON  F.  HODGE,  Ph.D. 

PROFEABOB  OF  SOCIAL  BIOUXJY   IX  THE   ITNIVEK8ITY   OF  ORFXK>N 
AUTHOR  OF  "XATtKE  STUDY  AND  LIFE" 

AND 

JEAN  DAWSON,  Ph.D. 

DBFABTMRNT  OF  SANITATION,  BOAKD  OF   IIKALTH,  CLKVELANP 

rOBMERLY   OF  MACIM»NALI>  roLI.KOE,  CANADA,  AND  C'LKVELAND   NOKMAL 

SCHOOL;   AI'THOR  OF  "THE   BIOLOGY   OF   FHYKA"  AND 

"BOYS  AND  OIULS  OF  GARDEN   CITV  " 


It  will  loach  only  such  iwes  of  authority  a« 
are  necpssary  to  necure  cooperation  of  several  or 
many  people  to  one  end  ;  and  the  discipline  it  ^vill 
advocate  will  l)e  training  in  the  development  of 
coui)erative  good  will.  —  Charles  W.  Eliot. 


GINN  AND  COMPANY 

BOSTON     •    NEW    YORK     •    CHICAGO     •     LONI>ON 
ATLANTA     •     DALLAS     •     COLUMBUS     •     SAN    FRANCISCO 

LIBRARY 

UMTVERSITY  OF  CALIFORNIA 
•       DAVIS 


COPYRIGHT,  1918,  BY  CLIFTON  F.  HODGE  AND  .JEAN  DAWBON 

ENTEKED  AT   STATIONERS'  HALL 

ALL   RIGHTS   RESERVED 

318.10 


GINN  AND  COMPANY  •  PRO- 
rUlETORS  •  BOSTON  •  U.S.A. 


PREFACE 

Discovery  is  pushing  forward  in  every  direction  as  never 
before  in  the  history  of  the  world,  and  still  it  would  seem 
that  enough  is  already  known  to  make  living  well-nigh  ideal 
and  the  world  almost  a  paradise,  if  only  enough  people  knew. 
In  how  many  of  our  civic  units  does  ever^'  citizen  know 
enough  to  conserve  effectively  the  valuable  bird  life,  the  trees, 
the  soil,  and  water  on  his  own  premises,  to  exterminate  the 
rats  and  English  spaiTows,  the  flies,  mosquitoes,  and  San  Jose 
scale,  the  hookworms,  diphtheria,  and  tuberculosis  germs  ?  If 
every  individual  citizen  knows  enough  to  do  these  tlnngs, 
in  how  many  communities  do  all  the  people  know  enough 
to  cooperate,  —  to  work  together  Avith  efforts  so  timed  and 
planned  that  the  good  work  of  one,  or  of  all  but  one,  shall 
not  be  rendered  vain  by  the  failure  of  someone  else  to  do 
liis  part? 

The  tides  and  currents,  storms  and  floods,  of  living  nature 
are  too  vast  and  powerful  to  be  held  within  any  dikes  less  se- 
cure than  those  built  by  the  common,  united  effort  of  the  whole 
community.  The  measure  of  our  present  need  is  seen  in  the 
wastage  and  loss  that  is  streaming  tlu:ough  our  ineffectual 
defenses,  —  the  probably  not  less  than  five  hundred  thousand 
valuable  lives  sacrificed  annually  to  the  currents  of  prevent- 
able disease,  along  with  the  several  billions  of  dollars'  worth 
of  foods  and  other  property  swept  away  by  rats,  insects, 
weeds,  and  fungi.  How  much  higher  must  the  cost  of  living 
soar  before  we  begm  to  awake  from  the  dream  that  we  are 
a  scientific  and  efficient  people  ?     As  we  are  now  organized 

iii 

395807 


iv  CIVIC  BIOLOGY 

(or,  rather,  disorganized),  who  knows  whether  his  next- 
door  neighbors  know  what  to  do  in  solving  common  civic 
problems  ?  From  the  way  they  do  and  live  he  may  conclude 
that  they  do  not  know,  but  they  may  all  be  passing  the  same 
judgment  upon  him.  So,  instead  of  each  one  doing  his  civic 
part,  and  knowing  that  the  rest  are  doing  theirs,  we  are 
caught  at  every  turn  in  the  do-less  net  of  "  what  's-the-use- 
ness."  A  would  gladly  protect  his  birds,  but  not  to  feed 
Mrs.  B's  cats.  C  could  easily  extermhiate  his  own  flies,  but 
they  continually  swarm  over  from  D's  filthy  premises.  And 
so  it  goes  for  the  thousand  and  one  civic  problems,  —  at  every 
turn  the  deadly  question,  "  What 's  the  use  ?  "  How  can  we 
extricate  ourselves  from  this  net? 

Cooperative  good  will  is  the  essential  idea  in  civic  biology, 
as  it  is  in  the  progress  of  civilization  itself.  This  means  that 
civic  biology  consists  of  all  those  problems  whose  solution 
requires  cooperative  effort.  In  the  nature  of  the  case  we 
cannot  control  many  of  the  forces  of  living  nature  by  any 
amount  of  uncoordinated  individual  effort,  any  more  than  we 
can  turn  back  the  ocean  tides  by  haphazard  sweeping  with 
brooms.  The  problem  of  civic  biology,  therefore,  is  to  make 
it  possible  for  everyone  to  know  what  these  forces  are,  for 
good  or  for  ill,  and  to  understand  how  to  do  his  part  for  his 
own  good  and  for  that  of  the  community.  Cooperative  build- 
ing of  the  defenses  offers  our  only  hope  of  success,  and  our 
education  needs  to  be  so  organized  that  every  citizen  shall 
know  enough  to  stop  a  breach  the  mstant  he  sees  it. 

Acknowledgments  in  the  text  accompany  pictures  and 
other  contributions,  except  in  the  following  cases :  The  figures 
of  ticks,  in  Plate  IV,  are  rearranged  from  those  published 
by  the  United  States  Department  of  Agriculture  and  the 
United  States  Public  Health  Service.  The  upper  view  hi  the 
frontispiece  is  taken  from  a  photograph  looking  northward 


PREFACE  V 

down  the  Hood  River  valley,  Oregon,  across  the  gorge  of  the 
Columbia,  with  Mt.  Adams  in  the  background.  It  is  used 
by  the  courtesy  of  the  United  States  Reclamation  Service. 
The  lower  view  is  from  one  of  Bailey  Willis's  photographs  of 
Shingkung,  China,  and  shows  desert  conditions,  man-made 
within  the  short  space  of  about  the  last  two  centuries.  With 
complete  deforestation  of  the  mountains,  the  once  fertile 
valley  has  been  buried  under  the  wash  of  floods,  which, 
alternating  with  burning  droughts,  have  made  the  country 
uninhabitable.  We  are  indebted  for  use  of  the  print  to 
the   Carnegie   and  Smithsonian  institutions. 

The  idea  of  the  book  is  expressed  at  a  glance  in  the  fron- 
tispiece, the  question  "  Which  ?  "  being  applicable  to  every 
landscape  and  home  in  the  world. 

C.  F.  H. 

J.  D. 


CONTENTS 

CHAPTER  lAGE 

I.   Plan  of.  the  Coukse  as  a  Whole 1 

II.   Equipment,  Apparatus,  and  Libkaky 10 

III.  The  Insect  Problem 18 

IV.  Birds 2:] 

V.   Methods  of  Bird  Study  and  Special  Problems    .  35 

YI.    Tree  Study  and  Civic  Forestry 55 

VII.   Plant  Problems  :  Preservation  ok  Wild  Flowers, 
Control    of    Weeds,   Medicinal   and    Poisonous 

Plants 67 

VIII.    Home  PLANTiN<i  and  Landscape  Gardening  ...  77 
IX.   Practical  Bioloc;y  of  Agricultural  Production 

AND  Civic  Utilization  of  Land 1)1 

X.   Insect  Type  Problems  :    Important  Flies  ....  107 

XL   Insect  Type  Problems  :   Mosquitoes 12-3 

XII.   Insect  Type  Problems  :    Cabbage  Butterfly     .  186 

XIII.  Insect  Type  Problems:    Ants 141 

XIV.  Special  Problems  of  Insect  Controi 148 

XV.   Arachnids.    Problems  of  Spiders,  Mites,  and  Ticks  163 

XVI.    American  Mammal  Problems 169 

XVII.    The  Rat  Problem 173 

XVIII.    Fungi  :   Bacteria,  Yeasts,  Molds,  Mildews,  Ivusts, 

Smuts,  and  Mushrooms 186 

XIX.   Fungi     Continued:     Mushrooms,     Poisonous     and 

Edible 200 

XX.   Fungous  and  Bacterial  Diseases  of  Plants     .     .  207 

XXL    Bacteria 218 

XXII.   Bacteria  Continued  :  Laboratory  Methods      .     .  224 

vii 


viii  CIVIC  BIOLOGY 

CHAPTER  PAGE 

XXni.    Control  of  Bactp:rial  Diseases       .          .'    .     .     .  231 

XXIV.   Control  of  Animal  Parasites 258 

XXV.   Civic  Problems  Relating  to  Mollusks  ....  271 

XXVI.   Crustacea .285 

XXVII.   Problems  of  Fish  and  Fishing    .......  295 

XXVIII.   Amphibia  :  Sirens,  Proteans,  Salamanders,  Frogs, 

Tree  Frogs,  and  Toads 313 

XXIX.   Reptiles  :  Crocodiles,  Alligators,  Turtles,  Ter- 
rapins, Tortoises,  Lizards,  Snakes 321 

XXX.   Practical  Laws  of  Life 330 

XXXI.   Knowing  How  to  Know  How 346 

XXXII.   Progress  in  Discovery 355 

INDEX 363 


Working  together  will  be  one  of  its  fundamental  ideas,  —  of  men  with 
God,  of  men  with  prophets,  leaders,  and  teachers,  of  men  with  one  another, 
of  men's  intelligence  with  the  forces  of  nature.  It  will  teach  only  such  uses 
of  authority  as  are  necessary  to  secure  cooperation  of  several  or  many  peo- 
ple to  one  end ;  and  the  discipline  it  will  advocate  will  be  training  in  the  devel- 
opment of  cooperative  good  will.  —  Eliot,  '^  Religion  of  the  Future,"  p.  22 

Physical  forces  or  the  exhaustion  of  purely  physical  resources  never  have, 
and  for  at  least  five  million  years  in  the  future,  so  the  astronomers  tell  us, 
cannot  extinguish  human  civilizations.  Floods  or  volcanic  eruptions  may 
cause  small  and  local  effects ;  while  biological  forces  are  oceanic,  subtile,  all- 
pervasive,  continuously  active,  ever  ready,  whenever  a  break  in  the  vital 
defenses  of  knowledge  occurs,  to  surge  in  and  obliterate  individual,  nation, 
civilization.  Even  the  great  movements  of  human  races,  conquests  and  wars, 
are  not  so  all-annihilating  in  their  effects  as  the  ceaseless  struggle  of  man- 
kind against  other  living  species.  Disease,  pestilence,  plague,  and  famine 
have  taken  their  millions  to  war  its  scores. 

These  forces  are  so  powerful,  so  vast  in  their  sweep,  that  for  one  individ- 
ual to  attempt  to  cope  with  them  is  like  Mrs.  Partington  trying  to  sweep 
back  the  ocean  with  her  broom.  Our  education  must  be  so  organized  that 
each  may  know  and  do  his  part. 

It  is  not  labor,  not  capital,  not  land,  that  has  created  modern  wealth  or 
is  creating  it  to-day.  It  is  ideas  that  create  wealth,  and  what  is  wanted  is 
more  ideas  — more  uncovering  of  natural  reservoirs,  and  less  labor  and 
capital  and  land  per  unit  of  production.  .  ,  . 

Muscular  effort  can  be  stimulated  by  the  lash  —  intelligent  supervision, 
intellectual  production,  never  !  One  single  idea  may  have  greater  value  than 
all  the  labor  of  all  the  men,  animals,  and  engines  for  a  century.  The  age  of 
muscular  human  effort  and  of  the  lash  is  passing  away,  and  the  old  morality 
with  it :  the  age  of  supervision,  of  cooperative  stimulus,  is  in  full  advance ; 
and  with  it  comes  a  new  morality,  under  which  the  Golden  Rule  can  be  ex- 
tended from  the  relations  between  individuals  to  those  between  classes, 
nationalities,  and  races.  — Emerson,  "Twelve  Principles  of  Efficiency," 
pp.  x  and  xi 


CIVIC  BIOLOGY 

CHAPTER  I 
PLAN  OF  THE  COURSE  AS  A  WHOLE 

Motto  of  the  course :  "That  we  may  know  enough  to  work  together." 

United  effort  is  the  central  idea  in  civic  organization,  and 
its  extension  underlies  advance  in  civilization.  Civic  biology 
consists  in  that  group  of  problems  in  the  control  of  living 
nature  to  solve  which  requires  that  a  community  unite  in 
working  together  intelligently.  There  is  a  large  body  of 
such  problems  which  must  be  made  a  vital  part  in  the  edu- 
cation of  every  citizen,  for  in  no  other  way  can  they  ever 
be  solved. 

We  are  suffering  enormous  losses,  —  in  destruction  of  nat- 
ural resources,  in  unfruitful  labor,  in  damage  to  property,  in 
preventable  disease,  —  due  to  lack  of  proper  civic  organiza- 
tion. One  ignorant  or  careless  member  of  a  community  may 
kindle  a  forest  fire,  or  clear  a  watershed  that  will  cause  a 
water  famine  over  an  extensive  territory.  He  may  permit 
insects  or  vermin  to  breed,  or  allow  fungi  or  bacteria  to  grow, 
that  will  cause  great  damage  to  property,  and  disease  and  even 
loss  of  life  among  his  neighbors. 

It  is  a  slight  matter  to  extinguish  a  match  or  a  camp  fire ; 
it  may  require  the  strenuous  efforts  of  thousands  to  cope 
with  a  burning  forest.  So  with  every  member  of  a  commu- 
nity cooperating  intelligently,  slight  effort  may  achieve  great 
results,  utterly  impossible  unless  all  work  together. 


2      .  .r.:'.,.  :Avfc'mb;-oGY 

As  an'iliiistrktwn/take/rfie'calse  of  the  common  rat.  These 
animals  are  probably  costmg  the  country  $500,000,000  annu- 
ally in  spread  of  disease,  in  damage  to  buildings,  merchandise, 
and  produce,  and  in  cost  of  traps,  poisons,  and  labor;  and 
since  bubonic  plague  has  gained  a  foothold  in  America,  they 
positively  must  be  exterminated.    A  single  pair  may  breed 


Kats,  where  they  all  l)elong 


1250  rats  in  a  year.  As  we  are  now  doing.  Smith  attempts  to 
rid  his  premises  of  the  pests  in  October,  driving  many  of  them 
over  to  Jones.  Jones  undertakes  the  work  in  November,  driv- 
ing them  back  to  Smith,  and  in  December  both  are  practically 
where  they  were  before.  The  same  amount  of  effort,  properly 
coordinated,  might  have  proved  effective.  This  principle  ap- 
plies with  added  force  to  larger  groups,  and  it  is  quite  possi- 
ble that  with  even  less  expense  and  labor  than  is  now  almost 


PLAN  OF  THE  COURSE  AS  A  WHOLE 


3 


wasted  annually,  the  rat  could   be   exterminated  from  the 
continent  within  a  year  or  even  witljin  a  single  month. 

Civic  organization  applies  not  only  to  the  control  of  injuri- 
ous forces,  but  equally  to  saving  valuable  species  from  exter- 
mination. Lacking  such  organization,  a  number  of  species  of 
great  value  have  already  been  exterminated  from  vast  areas, 
and  several  more  are  in  immuient  danger.    A  few  of  these. 


Fk;.  2.  Virginia  deer 
Photograph  by  George  Shiras 

chiefly  among   our  game   birds  and   game   and    fur-bearing 
animals,  will  receive  attention  in  the  appropriate  chapters. 

At  best,  among  the  great  number  of  such  problems,  we  shall 
be  able  to  study  only  a  few  typical  ones  that  touch  the  life 
of  the  community  most  vitally.  Three  or  four  insect  types 
are  all  we  shall  have  time  for,  but  thousands  of  others  may 
be  studied  by  similar  methods.  The  purpose  of  the  course  is 
thus  to  cultivate  habits  of  observation,  insights  into  the  work- 
ings of  living  nature,  and,  above  all,  civic  ways  of  thinking  and 
civic  methods  of  studying  and  of  attacking  such  problems  ;  and 


4  CIVIC  BIOLOGY 

the  highest  product  of  the  course  will  be  citizens  who  know 
enough  to  work  together. 

Select  the  problems  that  your  community  needs  to  have 
studied  most.  A  single  problem  actually  worked  out  to  a 
definite  civic  advance  will  be  worth  more  educationally  than 
a  hundred  problems  memorized  from  a  book. 

With  the  school  year  arranged  as  it  is,  it  will  be  neces- 
sary to  start  many  different  lines  of  work  in  the  early  fall. 
A  store  of  material  must  be  collected  for  use  during  the 
winter,  and  as  far  as  possible  this  should  be  done  by  the 
class,  —  to  give  practice  in  collectmg,  insight  into  problems, 
and  at  least  glimpses  of  the  various  forms  in  their  natural 
environment.  1 

In  order  to  collect  intelligently  and  plan  and  organize  the 
work  of  the  year,  first  run  through  the  book  rapidly  and  copy 
into  a  pocket  notebook  the  names  of  all  the  birds,  insects, 
fishes,  trees,  and  so  on,  described  in  the  text.  Estimate  im- 
portance of  topics  and  leave  required  space  for  notes  between 
the  names ;  page  and  make  an  alphabetical  index  at  the  back 
of  the  notebook.  This  gives  a  place  where  every  observation 
made  during  the  year  may  be  recorded  and  referred  to  in- 
stantly when  wanted.  Indent  margins,  date  and  space  so  that 
each  note  shall  stand  out  clearly.  Records  at  the  end  of  the 
year  may  read  about  as  follows :  ^ 

White  Pine  (Pinus  strohus) 

Sept.  3.  Noted  on  a  trip  into  the  country  that  the  squirrels  were 
cutting  quantities  of  the  cones  from  the  tops  of  the  pine 
trees  and  were  feeding  on  the  ripe  seeds.  The  cones  were 
closed  and  green,  but  the  seeds  were  brown  and  ripe  inside. 
Gathered  nearly  a  bushel  and  spread  on  papers  in  the  attic. 

1  This  outdoor  work  is  such  a  vital  part  of  the  course  that  careful  record 
should  be  kept  of  all  types  collected,  and  this  should  be  understood  to  form 
the  basis  for  a  definite  percentage  or  part  of  the  pupils'  required  standing. 

2  A  field  notebook  with  printed  index  and  topics  is  being  planned  to 
accompany  this  course. 


PLAN  OF  THE  COURSE  AS  A  WHOLE 


Jan.  10.  Found  cones  dry  and  wide  open,  with  many  of  the  seeds 
fallen  out.  Brought  enough  to  laboratory  to  supply  the  class.^ 

Feb.  22.  Planted  in  a  flat,  10  by  15  inches,  3  inches  deep,  200  seeds, 
with  the  wings  intact.  The  flat  was  filled  with  leaf  mold 
mixed  with  sand,  and  seeds  were  planted  about  J  inch  deep. 

March  15.    Seeds  beginning  to  germinate  (Lab.  Book,  p.  77). 

April  10.  Made  a  seed  bed  according  to  directions  in  Forest 
Service  Circular  67,  and  planted  all  •the  seed  I  had  left. 
Transplanted  seedlings  not  used  in  laboratory  into  this  bed. 


Fig.  3.  Type  collection,  white  pine 

1  It  is  supposed  that  this  pupil  undertook  to  supply  the  class  with  speci- 
mens of  the  white  pine,  other  members  of  the  class  doing  the  same  for  other 
trees.  References  to  the  laboratory  book  mean  that  on  pages  77  and  78  will  be 
found  drawings  of  the  specimens,  —  the  leaf  bundle,  with  possibly  a  sketch  of 
a  tree,  the  cone,  the  cone  scale  with  the  seeds  in  place,  the  seedlings  in  two 
or  three  stages  of  germination,  and  finally  the  flowers.  He  will  also  be  able 
to  tell  the  class  about  methods  of  collecting,  storing,  and  planting  the  seeds. 


C;iVIC  BIOLOOY 

May  7.    Buds  beginning  to  shoot.    Seedlings  coming  up  thick. 

June  8.  Collected  blossoms,  staminate  and  pistillate,  together 
with  cones  one  year  and  two  years  old  on  same  branches 
(Lab.  Book,  p.  78). 

Seedlings  3  inches  high.  Estimated  that  there  are  5600  in  my 
seed  bed. 

The  Humming  Bird  (Ti-ocJiilus  coluhris^ 

Sept.  6.    Seeft  daily  about  cannas,  nasturtiums,  etc. 

Sept.  12.  Saw  last  birds,  I  think.  One  alighted  for  a  moment 
on  bare  twig  and  flew  south. 

Oct.  3.  Found  deserted  nest  while  picking  apples  (Lab.  Book, 
p.  14). 

May  14.    First  arrival  seen  this  spring,  and  first  reported  in  class. 

Grape  (Delaware) 

Sept.  9.  Selected  as  specimen  to  study  a  Delaware  planted  by 
myself  six  years  ago  (Lab.  Book,  p.  42 ;  sketch  of  vine,  size 
of  stock,  area  of  trellis  covered,  drawing  of  cluster  and  leaf). 
Garnered  grapes,  42  pounds  in  12  minutes. 

Nov.  3.  Pruned  vine  15  minutes.  Buried  a  bushel  of  bones  about 
roots  (Lab.  Book,  p.  43  ;  diagram  of  vine  after  pruning). 

April  27.    Buds  beginning  to  shoot. 

May  15.  Placed  a  cane  6  feet  long  in  trench  3  inches  deep,  for 
layers. 

JuxE  19.    Blossoms  open,  new  shoots  about  2  feet  long. 

Codling  Moth  (Carpocapsa  pomonella) 

Sept.  21.  Examined '  100  apples  and  found  92  worm-eaten. 
Found  15  larvai  in  the  apples ;  the  rest  had  completed  their 
growth  and  gone.    Where  did  they  go  ? 

Sept.  22.  In  one  hour's  search,  scraping  apple  bark,  found  163 
larvae  in  their  cocoons  under  the  bark  scales.  They  must 
have  gone  there  when  they  left  the  apples. 

Xov.  28.  Observed  a  downy  woodpecker  at  work  on  apple  tree. 
From  8  to  8:15  saw  him  drill  intQ  5  bark  scales  and  remove 


PLAN  OF  THE  COURSE  AS  A  WHOLE  7 

the  larvje.  Climbed  up  and  secured  the  punctured  scales  for 
my  collection.  At  this  rate  how  many  might  a  woodpecker 
eat  in  a  year  ?  Wish  I  could  follow  him  and  discover  how 
many  he  actually  destroys  in  a  day.  Put  marrow  bones  and 
suet  in  the  apple  trees  to  attract  woodpeckers  to  the  orchard. 

Dec.  6.    Refer  to  Lab.  Book,  p.  41  (sketch  of  larva,  etc.). 

April  12.  Hunted  one  hour  again  for  larvae  ;  found  only  8,  but 
have  observed  the  woodpeckers  working  on  the  trees  all 
winter,  and  counted  179  punctured  bark  scales  from  which 
the  larvae  had  been  removed.  Those  found  were  still  in  the 
larval  stage. 

May  15.  Apple  trees  in  bloom.  Hunted  one-half  hour ;  found 
1  larva  and  2  pupae  (Lab.  Book,  p.  42). 

June  11.  Apples  about  the  size  of  marbles.  8  p.m.,  hung  a  lan- 
tern in  a  tree  where  apples  were  thickest.  Caught  a  moth 
in  act  of  laying  an  egg  on  an  apple.  As  I  raised  my  net  to 
catch  another,  a  bat  flitted  by  and  snapped  it.  Tried  to 
catch  bat  but  he  was  too  quick  for  me. 

The  main  laboratory  for  this  course  is  the  out-of-doors,  — 
the  yard,  garden  and  orchard,  streets  and  roadsides,  pastures, 
fields,  woods,  streams,  lakes,  hills,  and  swamps.  Thousands 
of  interesting  things  are  happening  out  there  all  the  while,  and 
it  is  there  the  student  must  go  if  he  would  really  learn  his 
lessons.  With  definite  assignments  of  what  to  seek  or  to  study 
and  observe,  most  of  this  field  work  should  be  done  either 
singly  or  in  small  groups  of  two  or  three.  In  addition  to 
this  there  should  be  individual  problem-working  and  lesson- 
learning  for  discussion  and  demonstration  of  the  more  general 
problems,  such  as  the  study  of  habitats ;  the  struggle  for  life 
as  seen  in  a  dense  woods ;  the  distribution  of  a  number  of 
the  types  studied  in  the  course ;  migration  of  birds ;  recog- 
nition of  trees,  birds,  common  plants.  A  number  of  special 
field  trips  also  should  be  arranged.  The  success  or  failure  of 
these  will  depend  upon  the  teacher's  knowledge  of  the  locality 


8  CIVIC  BIOLOGY 

and  of  the  times  and  seasons  for  the  appropriate  lesson.^  The 
course  supposes  at  least  seven  field  excursions:  two  in  the 
fall,  for  general  outlines ;  one  in  dead  winter,  for  recognition 
of  trees,  study  of  animal  tracks  and  doings,  winter  birds, 
hiding  places  of  insects  ;  and  four  in  the  early  and  late  spring. 
In  these  excursions  plan  to  take  in  a  model  dairy,  vineyard, 
orchard,  nursery,  tuberculosis  sanitarium,  fish  hatchery,  bird 
sanctuary,  or  other  local  institutions  of  interest. 

Fall  is  the  most  favorable  season  of  the  school  year  in  which 
to  study  insects  and  to  begin  the  study  of  birds.  The  largest 
share  of  the  time  usually  spent  in  "  learning  "  lessons  out  of 
books  or  in  the  indoor  laboratory  will  be  devoted  to  collect- 
ing and  studying  specimens  out  of  doors.  Hunt  particularly 
for  the  species  required  by  the  course.  There  are  so  many 
thousands  of  different  insect  species  that  you  will  soon  find 
yourself  bewildered  and  discouraged  if  you  try  to  study 
them  all.  Any  insect  of  special  importance  in  your  locality, 
however,  may  be  substituted  for  those  in  the  course,  if  de- 
sired. Collect,  so  far  as  possible,  the  complete  story  of  the 
life  and  work  of  each  species, —  eggs,  larva3,  pupae  and  adults 
(male  and  female),  injured  fruit,  eaten  leaves,  stings,  galls, 
and  the  like. 

While  working  over  the  ground  for  insects  it  will  require 
but  little  additional  time  to  collect  the  materials  for  several 
other  lines  of  work  to  be  done  in  the  laboratory  during  the 
winter.    Among  the  more  important  will  be : 

Leaves  and  fruits  of  forest  trees. 
Fruits  and  seeds  of  common  plants. 
Weeds  and  their  seeds. 

Common  mushrooms  and  tree-destroying  fungi. 

As  many  as  possible  of  the  parasitic  fungi  described  in  the  text,  — 
mildews,  blights,  rusts,  and  smuts. 

1  It  will  often  be  necessary  for  the  teacher  to  keep  careful  watch  and  go 
over  the  ground  himself  the  day  before  a  general  field  trip. 


PLAN  OF  THE  COURSE  AS  A  WHOLE  9 

Deserted  birds'  nests  for  study  of  nesting  sites,  and  analysis  of  mate- 
rials. Attach  a  label  to  each  nest,  stating  locality  and  position,  kind  of 
tree,  distance  from  ground,  etc. 

Fresh-water  olams  and  snails,  with  duckweed,  milfoil,  stonewort, 
and  other  aquatic  plants  common  to  the  locality,  for  use  in  stocking 
aquaria  during  the  winter. 

Fronds  of  all  the  common  ferns,  fruiting  and  sterile.  These  should 
be  pressed  between  sheets  of  paper  and  preserved  dry. 

The  ants'  nests  must  be  stocked  as  early  as  possible,  and  may  be 
maintained  through  the  winter. 

It  is  not  advisable  to  try  to  keep  frogs,  salamanders,  newts,  turtles, 
snakes,  or  many  fishes  in  the  laboratory  during  the  winter,  since  their 
normal  period  of  hibernation  will  be  interfered  with  and  they  are  not 
likely  to  do  well.  These  may  all  be  collected  and  studied  to  better 
advantage  in  the  spring. 

Ill  general,  the  order  of  chapters  follows  that  mdicated 
above :  insects  and  birds  with  beginning  plant  lessons  in  the 
fall ;  fungi,  bacteria,  and  animal  parasites  for  indoor  work 
during' the  whiter;  fishes  and  amphibia  in  early  spring;  and 
the  emphasis  on  plants  with  the  completion  of  bird  and  insect 
studies  in  the  later  spring  months.  A  natural  conclusion  of 
the  course  is  supplied  by  a  brief  statement  of  the  principles 
and  laws  of  life  with  an  outlook  toward  the  biological  organ- 
ization of  the  nation.  At  best,  with  so  many  interests  weav- 
ing a  continuous  pattern  through  the  cliangmg  life  of  the  year, 
the  text  will  need  to  be  used  as  a  reference  book  rather  than 
as  a  series  of  consecutive  lessons. 


CHAPTER  II 
EQUIPMENT,  APPARATUS,  AND  LIBRARY 

Laboratory  outfit.  Equipment  for  the  more  special  problems 
will  be  described  in  appropriate  chapters,  but  there  are  a  few 
general  needs  which  should  be  understood  at  the  outset.  First 
of  all,  the  course  demands  more  than  usual  individual  storage 
room  for  students'  material.  Each  student  should  have  not 
less  than  6  square  feet  of  shelf,  closet,  or  locker  space.  This 
will  be  supplied  by  a  simple  wall  case  1  foot  wide,  18  inches 
deep,  and  3  feet  tall,  with  three  shelves  about  9  inches  apart. 
The  student  must  be  given  time  to  label  and  store  his  speci- 
mens neatly,  since  any  appearance  of  "rubbish"  about  the 
laboratory  is  likely  to  prove  fatal  to  the  morale  of  the  whole 
course. 

The  laboratory  should  be  provided  with  at  least  two  good- 
sized  aquaria  and  two  vivaria.  A  convenient  size  for  all  of 
these  is  24  inches  long,  12  inches  wide,  and  15  or  18  inches 
deep.  They  may  all  be  made  according  to  directions  given 
below  for  aquaria  and  then  be  used  either  as  aquaria  or  viva- 
ria. Each  student  should  have  also  a  small  aquarium,  —  about 
12  inches  deep,  10  inches  long,  and  6  inches  wide,  —  which 
may  be  used  nearly  dry,  for  insect-rearing  cases;  moist,  for 
salamanders,  toads,  frogs,  and  tree  frogs  ;  or  filled  with  water, 
for  fishes  and  other  aquatic  animals  and  plants.  By  partially 
filling  such  aquaria  with  loam,  sawdust,  or  sphagnum,  covering 
the  outside  closely  with  black  paper,  tilting  slightly,  and  plant- 
ing different  seeds  close  against  the  glass,  they  may  serve  for 
interesting  demonstrations  in  germination  and  the  development 
of  root  systems. 

10 


EQUIPMENT,  APPARATUS,  AND  LIBRARY    11 

Individual  apparatus.  In  addition,  the  outfit  of  each  stu- 
dent should  contain  the  following :  one  insect  net,  one  small 
scrim  net  for  collecting  in  water,  one  cyanide  bottle,  one 
paper  of  assorted  insect  pins,  one  dozen  insect-mounting  cases 
(assorted  sizes),  and  two  notebooks  (one  pocket  size  for  field 
notes  and  data  of  field  collections,  the  other  larger,  unruled. 


FiCx.  4.  Making  insect  nets 

for  laboratory  notes  and  drawings).  These  should  be  paged 
and  indexed  for  quick  reference  from  one  to  the  other. 

A  vital  feature  of  the  course  is  the  making  of  simple  appa- 
ratus by  the  students  themselves.  Since  time  in  the  fall  is  so 
precious  for  outdoor  work,  the  necessary  apparatus  should  be 
provided  to  begin  with,  but  after  the  first  year  it  should  be 
made  by  the  previous  class ;  that  is,  each  class  should  take 
a  turn  at  making  apparatus  durmg  the  winter  in  order  that 
the  laboratory  m  ly  be  well  equipped  for  the  work  of  the  fol- 
lowing autumn.   Since  it  is  to  be  hoped  that  the  students  will 


12 


CIVIC  BIOLOGY 


continue  the  study  after  the  course  is  completed,  it  would  be 
well  if  each  could  be  given  the  chance  to  make  at  least  the 
two  collecting  nets  and  a  small  aquarium  for  himself. 

Materials  for  making  the  nets.  Flat-drawn  spring  brass  or  tinned  steel 
wire  for  the  frames  for  the  air  and  water  nets  respectively ;  the  strong- 
est cotton  tape  (mill  tape,  such  as  is  used  in  wrapping  electric  wires, 


Fig.  5.  Easy  construction  of  insect  net 
1,  form  of  wire  frame ;  2,  slipping  net  on  frame ;  3,  net  bound  to  handle  with  twine 

is  good) ;  then  for  the  air  nets,  strong  bobinet,  light  cheesecloth,  or 
mosquito  netting,  according  to  preference.  Mosquito  netting,  if  the 
threads  which  cross  run  the  long  way  of  the  net  and  care  is  observed 
to  avoid  water  and  briars,  makes  a  fairly  serviceable  insect  net.  For 
the  water  nets  use  cotton  scrim.  There  are  several  ways  of  making  the 
nets,  but  for  nets  detachable  from  the  handles  the  writer  has  found  the 
method  shown  in  Fig.  5  most  serviceable. 

Materials  for  aquaria.    The  aquaria  may  be  made  for  little  more  than 
cost  of  glass,  the  materials  being : 


EQUIPMENT,  APPARATUS,  AND  LIBRARY    13 


Glass.  Double-thick  window  glass  for  sides  and  ends,  and  ribbed 
skylight  glass  for  bottom  for  sizes  above  20  x  10  x  12  inches. 
For  smaller  sizes,  waste  10  x  12  in.  negatives  are  good  and 
cost  little  or  nothing. 

Angle  or  valley  tin,  sizes  indicated  Vjelow. 

Aquarium  cement. 

Solder. 

Green  or  black  carriage  paint  and  a  little  spar  varnish. 


Fig.  6.  Making  aquaria 

From  left  to  right,  laying  the  cement :   glass  set  in  one,  with  bent  green  twigs 

to  hold  it  in  place ;  painting  frames,  and  frames  of  different  sizes,  5x7x4  to 

24  X  15  X  10 ;  cutting  the  angle  tin  to  measure ;  soldering  the  frame  held  in  a 

square  fastened  to  table 

Tools.  Every  laboratory  should  be  provided  with  a  few  simple  tools, 
among  which  the  following  will  be  required  in  making  aquaria : 

Carpenter's  square, —  to  hold  the  frame  perfectly  square  at  each 
angle  while  it  is  being  soldered.  A  three-way  square,  made  by  nailing 
two  5-inch  boards  of  convenient  length  at  exact  right  angles  and  fasten- 
ing them  to  a  work  table,  greatly  facilitates  getting  each  angle  right  at 
the  first  trial. 


14 


CIVIC  BIOLOGY 


Tinsmith's  snips  and  square-nosed  pincers,  for  cutting  and  bending 
the  angle  tin. 

A  soldering  outfit,  —  soldering  iron  and  fluid  or  resin,  and  some  safe 
and  convenient  means  of  heating  the  iron. 

If  the  tools  are  not  at  hand,  the  frames  may  be  made  at  the  tinsmith's ; 
or  often  a  handy  Janitor  can  make  them  in  his  shop,  or  a  good-natured 
one  may  let  the  boys  use  his  tools,  if  they  are  very  careful  to  leave  every 
tool  in  its  place  and  the  shop  in  better  order  than  they  find  it. 

Dimensions  for  the  frames  are  given  in  the  table  below.  "'  Three- 
cross  "  tin  is  heavy  enough  for  all  smaller  sizes,  and  "  four-cross  "  for 


% 


v-'^vv:EZSI2Z2ZZi) 


Fig.  7.  Showing  relations  of  frames,  cement,  and  glass  in  aquaria, 
of  different  sizes 

a,  for  the  larger  sizes ;  b,  for  smaller  sizes ;   c,  arrangement  at  top  and  cover. 
Black  lines,  metal ;  flashed  areas,  glass ;  dotted  surface,  cement 


aquaria  between  15  and  24  inches  in  length.  The  more  slender  the 
frame  the  trimmer  and  better  the  aquarium  appears.  For  aquaria-dimen- 
sions in  inches : 

5  X  7  X  4  to  8  X  10  X  5  :  use  |-inch  angle  tin. 
10  X  12  X  6  to  8  X  10  X  5  :  use  i-inch  angle  tin. 
15  X  12  X  8  to  18  X  15  X  9  :  use  |-inch  angle  tin. 
20  X  12  X  9  to  24  X  18  X  12  :  use  1-inch  angle  tin  (around  base, 

and  if  the  work  is  carefully  done,  f-inch,  or  even  ^inch,  is 

strong  enough  for  the  rest). 

Fig.  7  gives  the  relation  of  cement  to  the  angle  tin  and  the  glass  for 
large  and  small  sizes.    In  the  larger  sizes  the  strip  of  glass,  with  the 


EQUIPMENT,  APPARATUS,  AND  LIBRARY         15 

prism  of  cement  behind  it,  strengthens  the  angle  and  also  protects  the 
water  from  a  large  surface  of  cement,  which  might  yield  up  enough  of 
its  lead  to  injure  delicate  animals. 

Lids  may  be  made  either  of  perforated  tin,  with  the  edges  turned  over 
to  stiffen  them,  or  of  wire  screen  fastened  to  either  wooden  or  tin  frames. 
The  lids  will  be  needed  when  the  aquaria  are  used  as  insect-breeding 
cages  and  for  feeding  tests  with  toads,  frogs,  or  other  insectivorous  ani- 
mals. The  hinges  of  brass  or  tin  should  be  soldered  to  the  frames  when 
they  are  made.    These  points  are  sufficiently  illustrated  in  Fig.  7. 

Aquarium  cement.  The  formula  used  by  the  United  States  Fish  Com- 
mission is :  by  weight  6  parts  whiting,  1  part  red  lead,  1  part  litharge ; 
mix  thoroughly  while  dry,  and  as  required  for  use  make  into  a  stiff 
putty  with  pure  linseed  oil.  The  oil  must  be  free  from  any  trace  of 
adulteration  with  fish  oil,  or  the  cement  is  likely  to  remain  soft  and 
sticky.  Do  not  expect  the  cement  to  "  set "  hard.  If  it  did  this,  the 
expansion  and  contraction,'  under  changes  of  temperature  of  metal  and 
glass  with  which  it  is  associated,  would  be  likely  to  crack  either  the 
glass  or  the  cement.  It  should  remain  as  a  tough  gum,  solid  enough  to 
support  the  pressure  of  water  and  pliable  enough  to  accommodate 
itself  to  changes  of  temperature. 

Lay  the  right  amount  of  cement  in  all  the  angles  of  the  frame  with 
a  putty  or  case  knife,  and  press  the  glass  for  bottom,  sides,  and  ends 
into  place  in  the  order  named ;  smooth  all  joints  on  the  inside,  removing 
any  extra  cement ;  spring  pliable  green  twigs  against  the  sides  and  ends 
to  hold  them  in  place,  and  smooth  up  the  outside  joints.  It  is  2:)refer- 
able  to  paint  the  frame,  letting  the  paint  dry  well,  before  setting  the 
glass.  A  coat  of  spar  varnish  along  the  angles  on  the  inside  will  protect 
the  cement  frorii  contact  with  the  water  and  also  insure  against  leaks. 
Leaks  seldom  occur,  but  if  they  do,  mark  them,  dry  the  aquarium 
thoroughly,  press  a  little  cement  into  the  cracks,  and  give  another 
coat  of  spar  varnish  to  the  inside  corners.  After  drying  for  a  week,  the 
aquarium  is  ready  to  use. 


Note.  It  is  easier  to"  avoid  daubs  of  cement  than  to  clean  them  off  the 
glass.  The  same  applies  to  hands,  clothes,  tables,  floors,  and  everything  else. 
A  class  in  aquarium-making  can  easily  daub  themselves  and  the  laboratory 
so  as  to  disgust  all  concerned  with  the  work  ;  or,  by  the  use  of  a  few  news- 
papers, can  avoid  all  this  to  the  satisfaction  of  everybody.  Since  the  cement 
contains  lead,  it  is  better  not  to  let  it  come  into  contact  with  the  skin  jnore 
than  is  necessary.    Stir,  mix,  and  lay  it  with  proper  tools. 


16 


CIVIC  BIOLOGY 


THE  LABORATORY  BOOKSHELF 

(The  asterisk  indicates  books  of  special  importance  for  this  course) 

Nothing  so  inspires  to  good  work  on  a  subject  as  knowledge  of  what  is  already 
known  about  it;  hence  this  reference  bookshelf  is  the  vital  basis  of  the  whole 
course.  The  present  list  is  intended  to  be  merely  suggestive,  and  should  be  freely 
modified  to  suit  local  problems  and  diligently  kept  up  to  date.  On  every  subject 
you  study  obtain  the  latest  word  from  the  extension  department  of  your  state 
university,  your  agricultural  experhnent  station,  the  United  States  Department  of 
Agriculture,  Bureau  of  Education,  Bureau  of  Fisheries,  Smithsonian  Institution, 
and  local,  state,  and  national  health  departments. 


DoANK.   Insects  and  Disease. 
Emekton.    Common  Spiders. 
Holland.    Butterfly  Book. 
HoLLAxn.    Moth  Book. 
HowAKO.    The  House  Fly  —  Disease 

Carrier, 
*lvKLi>o<io.    American  Insects. 

Bird.^ 

*Bailky.    Handbook  of  Birds  of  the 

Western  United  States. 
*CnAi*MAN.    Handbook  of  Birds  of 

Eastern  North  America. 
*Reeu.    Bird  Guides.    Bart  I,  Water 

and  Game.  Partll,  Land  and  Song 

Trees  - 
*  Aim;  AH.    Trees    of     the     Northern 

United  States. 
*Gkeen.     Principles    of    American 
Forestry. 

General  Botaiuj 

*Beugen  and  Davis.    I'rinciples  of       *Osteriiol'i 

Botany. 
HiMTTOx   and   Bnowx.      Illustrated 

Flora  of  Northern  United  States. 
*(iuAY.    New  Manual  of  Botany. 

Funyi 


Insects,  etc. 

Mitchell.   Mosquito  Life. 
*Sauxdehs.     Insects    Injurious    to 

Fruits. 
ScrnDEK.    Everyday  Butterflies. 
*S-Mrm.     Our   Insect   Friends   and 

Enenlies. 


Western  Bird  Guide  (for  west  of 

the  Rocky  Mountains). 
*Traftox.     Methods  of  Attracting 

Birds. 
Weed  and  Deakhokx.  Birds  in  their 

Relation  to  Man. 


Forestry 
Sakgext.    Mamial  of 
North  America. 


the  Trees  of 


Experiments  with 
Plants. 

*Stevexs.    Illustrated  Guide  to 
Flowering  Plants. 


Atkixsox.    Mushrooms. 

*CoxN.  Bacteria,  Yeasts,  and  Molds 

in  the  Home. 
*DuGGAR.      Fungous     Diseases     of 

Plants. 
GoiiHAM.    A  Laboratory  Course  in 

Bacteriology. 


*JoHDAX'.    General  Bacteriology. 

McIlvaixe  and  Macadam.  One 
Thousand  American  Fungi. 

Russell  and  Hastings.  Experi- 
mental Dairy  Bacteriology. 


THE  LABORATORY  BOOKSHELF 


17 


Agriculture 


*BuRKETT,     Stevens,     and     Hill. 

Agriculture  for  Beginners. 
Cyclopedia  of  American  Agriculture. 

Vol.  I,  Farms. 

*Vol.  II,  Crops. 

*Vol.  Ill,  Animals. 

Vol.  IV,  Farms  and  the  Commu- 
nity. 


*Hoi'Kixs.  Soil  Fertility  and  Per- 
manent Agriculture. 

*KiNG.  Farmers  of  Forty  Centuries. 

*Plumb.  Types  and  Breeds  of  Farm 
Animals. 

WiLKixsox.    Practical  Agriculture. 


Animals  —  General  Zoology 

*LiNviLLE  and  Kklley.      General       Shalkr.    Domesticated  Animals'. 
Zoology. 

Fishes 

*JoRDAX  and  EvEKMAXx.   American       *rnited    States   Fish    Commission. 
Food  and  Game  Fishes.  Manual  of  Fish  Culture. 


Miscellaneous' 


*Allex.    Civics  and  Healtli. 

Darwix.    Earthworms. 

*Darwix.   Naturalist's  Voyage 
around  the  World. 

*Davexport.    Principles  of  Breed- 
ing. 

Dickersox.    Frog  Book. 

Ditmars.    Reptile  Book. 

GiBsox.   Sharp  Eyes. 


*HoDGE.    Nature  Study  and  Life.i 
*Horxaday.    American  Natural 

History. 
Lubbock.    Ants,  Bees,  and  Wasps. 

r  Shrubs. 
Neavhall.    <  Trees. 

[  Vines. 
Wallace.    Malay  Archipelago. 
Wheeler.    Ants. 


Journals 


Agricultural    Department    publica- 
tions. 
*Experiment  Station  Record. 
*Monthly  List  of  Publications. 
*Weekly  News  Letter. 
*Journal  of  Agricultural  Research. 


*American  Forestry. 

*  American  Journal  of  Public  Health. 
*Bird  Lore. 

*  Journal  of  Economic  Entomology. 
*Journal  of  Heredity. 

*School  Science  and.  Mathematics. 


^  "  Civic  Biology  "  presupposes  a  knowledge  of  the  problems  stated  in  this 
hook. 


CHAPTER  III 
THE  INSECT  PROBLEM 

Work  of  insects  in  nature.  Geologically  the  present  is 
known  as  the  age  of  man,  but  zoologically  it  is  the  age  of 
insects.  There  is  but  one  species  of  man,  —  Homo  sapiens^  — 
while  over  300,000  species  of  insects  have  been  described,  and 
it  is  estimated  that  in  all  there  are  not  fewer  than  10,000,000 
species  in  the  world.  The  number  of  individuals  of  any  one 
species  may  cover  the  forests  and  fields  or  even  darken  the 
skies  over  large  areas. 

Compared  with  other  animals  insects  are  small,  having 
developed,  instead  of  size,  refinement  of  mechanism  and  organ- 
ization and  great  reproductive  power.  This  latter  often  sur- 
passes belief,  but  since  it  shows  us  the  importance  of  natural 
checks  to  the  increase  of  insects,  it  must  form  one  of  the 
central  features  of  our  insect  lessons.  A  pair  of  San  Jose 
scales  could  produce  progeny  in  a  season  to  the  number  of 
3,216,080,400.  A  single  female  plant  louse  might  give  origin 
to  9,500,000,000,000  in  a  season  (Forbes).  The  house  flies  of 
a  city,  if  all  the  young  survived  and  could  find  food,  would 
bury  it  before  the  people  could  escape  (Jordan).  We  are  led 
from  these  facts  to  see  the  importance  of  insectivorous  animals ; 
for  example,  it  has  been  estimated  that  the  birds  of  Nebraska 
consume  daily  86,000  bushels  of  insects  during  the  warm 
months  (B runner). 

No  insects  are  used  for  food  by  civilized  man,  and  it  is 
remarkable  that  in  so  great  a  number  of  species  so  few  pro- 
duce anything  of  value  to  man.  Silk,  honey  and  beeswax, 
shellac  and  cochineal,  and  cantharides  virtually  complete  the 

18 


THE  INSECT  PKOBLEM  19 

list  of  important  products.  Many  insects  are  of  great  value  to 
man  indirectly,  because  they  destroy  other  insects.  The  great- 
est service,  however,  which  they  perform  in  nature  consists  in 
effecting  cross-pollination  of  flowers,  and  many  of  our  most 
valuable  fruits  and  flowers  would  be  infertile  without  their 
aid.  Fortunately  the  honeybee  is  the  most  valuable  insect  for 
this  work. 

In  contrast  to  the  value  of  these  few  insects,  however,  is 
the  great  injury  done  by  others  in  their  attacks  upon  man  and 
animals,  causing  annoyance,  suffering,  and  often  disease.  The 
majority  feed  upon  plants  and  thus  compete  with  man,  directly 
or  indirectly,  for  the  vegetable  food  supply  of  the  world.  Re- 
cent estimates  of  the  Department  of  Agriculture  divide  this 
damage  as  follows : 

Annual  Loss  of  Agricultural  Products  caused  by  Insects 
IN  United  States 

Cereals ,     .     .     .     .  $237,800,000 

Hay 66,000,000 

Cotton o     .     .     .     .  67,500,000 

Tobacco 6,900,000 

Truck  crops 68,000,000 

Sugars 6,400,000 

Fruits 66,000,000    • 

Farm  —  Forests     . 15,000,000 

Miscellaneous  crops 18,900,000 

Animal  products 267,000,000 

Katural  forest  products 130,000,000 

Products  in  storage 100,000,000 

Total $1,049,500,000 

These  estimates  are  conservative  and  relate  to  purely  agri- 
cultural losses.  They  do  not  include  the  damage  caused  by 
common  household  insects,  —  clothes  moths,  carpet  beetles, 
roaches,  ants,  and  several  human  parasites,  which  entail  great 
labor  and  expense  in  fighting  them.    The  annual  cost  of  wire 


^e  CIVIC  BIOLOGY 

screen  to  keep  flies  and  mosquitoes  out  of  houses  amounts  to 
at  least  112,500,000  annually.  Nor  does  the  above  estimate 
take  account  of  the  depreciation  of  property,  loss  of  time,  and 
cost  of  diseases  like  malaria  or  yellow  fever,  known  to  be  car- 
ried by  certam  mosquitoes,  infantile  paralysis,  carried  by  the 
stable  fly,  and  typhoid,  cholera  infantum,  dysentery,  and  many 
other  filth  infections  which  are  transmitted  by  common  house 
flies.  With  these  additions  it  is  safe  to  say  that  insects  annu- 
ally levy  a  tax  of  not  less  than  11,500,000,000  on  the  people 
of  this  country,  and  this  hi  addition  to  the  annoyance  and 
suffering  which  they  cause  to  human  and  animal  life. 

Work  for  control  of  insects.  Since  insects  possess  such  power 
of  rapid  increase,  and  smce  this  increase  is  limited  mainly  by 
food  supply,  natural  enemies,  and  artificial  means  of  destruc- 
tion, any  relaxation  of  natural  or  artificial  checks  tends  to 
permit  insects  to  increase  up  to  the  limit  of  food  supply.  With 
these  checks  entirely  removed,  insects  would  take  practically 
the  entire  agricultural  product  in  an  incredibly  short  time. 

The  relative  efliciency  of  natural  and  artificial  checks  is 
well  exemplified  by  a  number  of  cases  in  which  an  insect  has 
been  accidentally  introduced  from  some  other  continent  with- 
out bringmg  the  natural  enemies  of  the  species.  The  cottony 
cushion  scale  of  Australia  swept  over  the  orange  groves  of 
California  like  a  consuming  fire  until  its  natural  enemy,  the 
Vedalia  lady  beetle,  was  imported.  The  gypsy  and  brown- 
tailed  moths  in  Massachusetts  show  even  more  clearly  how 
ineffectual  human  effort  is  when  pitted  against  such  forces  of 
nature.  After  expenditure  of  several  millions  of  dollars  and 
twenty  years  of  futile  effort  we  are  brought  to  realize  that  our 
best  hope  of  permanent  success  lies  in  the  importation  of 
natural  insect  enemies.  The  San  Jose  scale,  accidentally  in- 
troduced from  Chma,  is  now  rapidly  exterminating  fruit 
orchards  and  ornamental  trees  over  almost  the  entire  country. 
In  1901,  Dr.  Marlatt  succeeded  in  importing  a  Chinese  lady 


THE  INSECT  PROBLEM  21 

beetle  (^Chilochorus  similis),  which  is  efficient  in  keeping  the 
scale  in  check  in  its  native  home.  It  has  not  as  yet  proved, 
however,  an  equal  success  in  America. 

Other  cases  in  point  are  the  Hessian  fly,  cabbage  butterfly, 
codling  moth,  elm-leaf  beetle,  imported  currant  fly,  and  many 
more ;  and  these  illustrate  the  almost  irresistible  power  of  an 
insect  species  when  supplied  with  abundant  food  and  relieved 
from  its  natural  enemies.  They  also  emphasize  the  need  of 
watching  all  ports  of  entry  with  extreme  care  to  prevent  such 
expensive  importations.  — ■ 

All  work  with  insect  enemies  reveals  the  absolute  necessity 
of  the  general  dissemination  of  a  knowledge  of  the  problems 
involved.  One  ignorant  or  careless  importation  may  cost  the 
whole  country  irreparable  loss.  A  neglected  garden  or  orchard 
is  often  a  menace  to  an  entire  neighborhood.  For  one  indi- 
vidual to  try  to  hold  such  natural  forces  in  check  is  discour-  f 
aging  and  well-nigh  hopeless.  In  the  successful  handling  of 
such  problems  all  members  of  a  community  must  unite.  Each  ^ 
must  know  and  do  his  duty  and  his  part/ "If  one  person  can- 
riot  or  will  not  prevent  his  trees  from  breeding  insect  pests 
that  damage  his  neighbors,  he  should  promptly  cut  them  down 
and  burn  them  up.  This  law  of  nature  applies  with  special 
force  to  the  intelligent  protection  of  birds  and  other  insec- 
tivorous animals,  in  which  all  members  of  the  community 
should  unite. 


-L 


CUCKOOS,  KINGFISHERS 


vj-^ 

•w^^ 

"-#; 

•'*!^ 

^_^ 

^ 

I'KRCIIERS 

i^21 


SWANS,  (JEESi:,  DICKS 

Fig.  8.  Orders  of  American  birds,  with  habitats 
22 


CHAPTER  IV 

BIRDS 

In  the  air  swallows  and  swifts  are  coursing  rapidly  to  and  fro,  ever  in 
pursuit  of  insects,  which  constitute  their  sole  food.  When  they  retire,  the 
nighthawks  and  whip-poor-wills  will  take  iip  the  chase,  catching  moths  and 
other  nocturnal  insects  which  would  escape  day-flying  birds.  The  flycatchers 
lie  in  wait,  darting  from  ambush  at  passing  prey,  and  with  a  suggestive 
click  of  the  bill,  returning  to  their  post.  The  warblers,  light,  active  crea- 
tures, flutter  about  the  terminal  foliage,  and  with  almost  the  skill  of  a  hum- 
ming bird,  pick  insects  from  leaf  or  blossom.  The  vireos  patiently  explore 
the  undersides  of  leaves  and  odd  nooks  and  corners  to  see  that  no  skulker 
escapes.  The  woodpeckers,  nuthatches,  and  creepers  attend  to  the  tree 
trunks  and  limbs,  examining  carefully  each  inch  of  bark  for  insects'  eggs 
and  larvae,  or  excavating  for  the  ants  and  borers  they  hear  at  work  within. 
On  the  ground  the  hunt  is  continued  by  the  thrushes,  sparrows,  and  other 
birds,  who  feed  upon  the  innumerable  forms  of  terrestrial  insects.  Few 
places  in  which  insects  exist  are  neglected  ;  even  some  species  which  pass 
their  earlier  stages  or  entire  lives  in  the  water  are  preyed  upon  by  aquatic 
birds.  —  Chapman,  "Bird  Life,"  p.  C 

As  planned  for  this  course,  bird  study  begins  with  the  open- 
ing of  school  in  September  and  continues  throughout  the 
year.  No  subject  better  repays  attention.  On  the  esthetic  side 
it  presents  infinite  possibilities  for  the  discovery  of  beauty  in 
grace  of  form  and  action,  in  harmony  of  color,  and  in  variety 
of  song.  From  the  standpoint  of  science  and  pure  natural 
history,  no  field  is  richer,  —  variety  in  size  and  form,  instincts 
and  intelligence,  protective  and  recognitional  coloring,  geo- 
graphical distribution,  pathways  of  migration,  and  even  the 
geological  record  showing  the  evolution  of  birds  from  reptiles. 

Birds  and  insect  destruction.  In  order  that  universal  and 
adequate  protection  may  be  extended  to  all  valuable  species, 
every  member  of  the  nation  should  know  what  the  birds  are 

23 


24  CIVIC  B10L()(^Y 

doing  for  the  common  go(  kI.  From  an  earlier  chapter  we  have 
learned  of  the  enormous  tax  which  insects  impose.  The  chief 
economic  service  of  birds  consists  in  the  destruction  of  insect 
pests,  and  our  national  bill  of  insect  damage,  $1,049,500,000, 
may  be  roughly  taken  as  a  measure  of  our  deficiency  in  bird  life. 

Reed  estimates  that  with  5  birds  to  the  acre  and  100 
insects  daily  per  bird,  the  birds  of  Massachusetts  require  for 
food  each  day  during  five  months  of  the  year,  2,560,000,000 
insects;  or,  allowing  120,000  insects  per  bushel,  21,000  bushels. 
The  work  of  winter  birds  and  migrants,  he  thinks,  amounts  to 
nearly  half  this  number  for  the  colder  months,  in  destruction 
of  hibernating  insects  and  eggs,  larvae  and  pupae.  A  chickadee 
has  been  known  to  eat  from  500  to  4000  eggs  hi  a  single  day. 

For  Nebraska,  Professor  Lawrence  Brunner's  estimate  is  as 
follows  : 

Taking  as  a  basis  for  our  estimations  the  figures  given  in  my  leaflet 
entitled  A  Plea  for  (he  Protection  of  Our  Birch,  we  would  have  about 
75,000,000  birds,  or  approximately  35,000,000  to  40,000,000  pairs  that 
nest  here  (Nebraska).  Should  each  pair  of  this  large  number  rear  four 
young,  there  would  be  required  a  sufficient  food  supply  for  from  140,- 
000,000  to  160,000,000  young  birds.  If,  as  we  suggested  in  that  paper, 
a  single  bird  requires  on  an  average  25  insects  per  day,  the  enormous 
number  of  4,000,000,000  insects,  or  35,000  bushels  of  120,000  insects, 
would  be  required  each  day  to  feed  the  J'^oung  birds  alone.  But  young 
birds  need  much  more  food  than  do  old  ones,  and  we  should  at  least 
double  this  quantity  for  the  young  birds.  Then  to  this  must  be  added 
tliat  required  by  the  parent  birds  themselves  while  taking  care  of  the 
young,  making  a  grand  total  of  86,000  bushels,  or  107  carloads  of  20 
tons  each,  provided  we  allow  50  pounds  as  the  weight  of  a  bushel. 

Feeding  tests  and  the  actual  observation  of  birds  from 
daylight  to  dark  have  given  us  our  most  valuable  data  with 
reference  to  the  destruction  of  insects  by  birds. 

A  female  wood  pewee  from  4.30  a.m.  to  6.52  p.m.  was  seen  to  catch 
568  insects.  A  brooding  bird  of  the  same  species  from  4.46  a.m.  to  6  p.m. 
caught  208.  The  first  was  feeding  her  nest ;  the  second  merely  catch- 
ing for  herself. 


BIRDS 


25 


A  pair  of  house  wrens  were  observed  to  feed  tlieir  nest  of  five  young 
—  five  days  old — ^230  insects,  most  of  them  large  cabbage  caterpillars; 
time,  4.24  a.m.  to  7.38  p.m. 

A  pair  of  orchard  orioles,  from  4.30  a.m.  to  O.lO  p.m.,  were  observed 
to  feed  the  nest,  containing  two  nearly  full-fledged  young,  09  times, 
probably  several  insects  at  a  feeding. 

A  pair  of  phoebes,  from  4.20  a.m.  to  7.12  I'.m.,  fed  two  young  2i)i) 
times.  A  young  phcebe  just  out  of  the  nest  recpiired  as  high  as  200 
good-sized  grasshoppers  per  day.^ 

A  young  robin  about  three  weeks  old  ate  70  large  cutworms  on  one 
day,  and  two  and  a  half  ounces  of  earthworms  the  next.  A  young  scar- 
let tanager  ate  150  cabbage  cateri)illars,  besides  other  food,  in  a  day. 
A  cuckoo  on 
the  tenth  day 
ate  42  grass- 
hoppers, 00 
woolly  cate)- 
pillars,and31) 
cabbage  cat- 
erpillars.  On 
the  twentietli 
day  the  same 
bird  consumed 
02  woolly  cat- 
erpillars, 123 

cabbage  cater-  ,,       ,...,,.        ,  .  ,     ,  ^       ,  ,     t-       i 

.,,     ®       _  .  ^  iiG.  9.  Bobwhite  cluck  three  weeks  old.    Lsual  occupation 
l>i  liars,  and  43 

.  Photograph  by  the  author 

grasshoppers,  &    i       j 

amounting  to  three  ounces  of  food.    An  adult  cuckoo  ate  225  cabbage 

cater] tillars,  or  150  large  woolly  caterpillars,  amounting  to  about  five 

ounces  of  food  daily.    (From  feeding  tests  by  Andrew  J.  Redmon.) 

From  such  actual  data  as  these  we  learn  that  the  estimates  given 

above  are  conservative.    Much  more  accurate  observation  is  required, 

however,  before  entirely  reliable  estimates  can  be  made. 

Outdoor  laboratory  work.  This  should  extend  throughout 
the  year,  and  also  to  combine  problems  requiring  continuous 


^  All  the  above  data  are  taken  from  reports  of  students  of  the  Indiana 
University  Summer  School,  Winona  Lake,  Indiana,  for  1905  and  1906 
(O.  P.  Dellinger  in  charge  of  class). 


26  CIVIC  BIOLOGY 

observations  upon  birds,  insects,  trees,  fungi,  weeds,  native 
flowers,  and  common  plants,  elaborate  the  following  plan  as 
early  in  the  year  as  possible.  Let  two  students  combine  upon 
the  same  tract  of  land,  in  order  to  secure  greater  completeness 
of  the  practical  work,  but  each  should  make  his  own  field  charts 
in  as  careful  detail  as  if  he  were  working  the  tract  alone. 

Select  some  readily  accessible  piece  of  land  of  limited  area. 
On  a  farm,  the  home  lot  with  the  dooryard,  garden,  orchard, 
and  grove  will  be  most  suitable.  The  village  lot  of  an  acre  or 
two  is  exactly  adapted  to  this  work.  In  an  open  city  the  home 
lot,  if  well  planted,  may  prove  the  best  selection  we  can  make, 
but  probably  the  residential  block  in  which  the  home  stands 
will  provide  necessary  variety  and  scope.  For  the  crowded 
city  we  must  have  recourse  to  public  parks  and  gardens,  and 
to  accessible  tracts  in  the  suburbs,  for  the  study  of  which  defi- 
nite permission  can  be  obtained.  The  tract  should  present,  if 
possible,  a  variety  of  natural  features,  —  hill,  meadow,  ravine, 
brook  or  edge  of  pond,  and  especially  variety  in  plant  forms, 
—  lawn,  garden,  orchard,  field,  meadow,  woods.  A  variety  of 
shrubbery  and  low-growing  trees  makes  a  tract  preferable  to 
one  with  very  tall  trees,  which  are  difficult  and  unsatisfactory 
to  work.  By  properly  dividing  the  neighborhood  among  the 
class,  however,  all  the  important  features  of  the  locality  may 
be  covered,  and  this  will  add  interest  and  completeness  to  the 
work  as  a  whole. 

As  a  preliminary,  draw  an  outline  map  to  convenient  scale, 
and  with  due  regard  to  points  of  the  compass.  Within  this, 
first  sketch  in  standard  contour  lines  and  indicate  location  of 
water,  marsh,  swamp,  rock  outcrops,  and  all  buildings  and 
superficial  subdivisions,  —  lawns,  gardens,  orchards,  fields, 
pastures,  woods. 

We  are  now  ready  to  plot  the  details.  Count  and  locate  all 
the  trees,  vines,  and  shrubs,  and  indicate  clearly  the  areas  cov- 
ered by  different  plants  or  crops.    Locate  all  birds'  nests  and 


STREET 


-«r#- 


spruce --^Mulberr 


O^    d    0 


Pear  ^     **-« 
Peach 

fe»  ©  t'^  %;^  ^  ■'G? 


Mb ''tin  House 


[ffi' " 


Vegetables 


1-- 


Gcoseoernes 


i    /I; 


Fig.  10.  An  ideal  bird-study  tract 
27 


28  (  IVIC  BIOLOGY 

determine  the  species  as  far  as  possible,  indicating  them  by 
some  device,  like  the  initial  letter  of  the  name,  on  the  plat. 
This  work  should  be  completed  as  soon  as  possible  after  the 
leaves  fall  in  November.  By  inquiiy  it  may  be  possible  to 
locate  nests  that  have  been  ''  collected  "  or  destroyed  by  storms 
during  the  summer.  Tliis  will  give  a  "  census  "  of  the  bird 
population  of  the  tract. 

The  main  question  which  this  investigation  is  designed  to 
answer  is,  Are  there  enough  birds  in  the  area  to  hold  the 
insects  in  check  ?  To  aid  in  answering  this  question  examine 
the  district  minutely  for  evidences  of  insect  depredations,  and 
make  a  list  of  important  msect  pests  found  upon  it.  Examine 
at  least  100  of  each  variety  of  apple,  pear,  quince,  possibly 
peach  and  plum,  and  tabulate  the  percentage  of  the  different 
fruits  injured  by  insects.  Gather  similar  data,  if  possible,  for 
the  earlier  fruits, —  strawberries,  gooseberries,  currants,  —  and 
also  for  the  various  garden  vegetables  and  other  crops  grown 
in  the  tract.  Add  to  the  bill  of  damage  the  cost  of  materials, 
apparatus,  and  labor  expended  in  fighting  insects.  On  the 
otlier  side  of  the  balance  sheet  record  with  equal  care  any 
injury  caused  by  birds.  Note  wliat  kind  of  birds  caused  the 
damage. 

From  all  you  know  and  can  learn  of  bird  life  try  to  discover 
what  special  features  attract  the  birds  to  nest  on  the  tract,  — 
water,  food,  suitable  nesting  sites  and  materials.  Suitable 
and  accessible  water  for  drinking  and  bathing  will  be  found 
to  be  one  of  the  main  factors,  and  food  supply  and  absence 
of  enemies,  other  elements.  Never  lose  an  opportunity  to  see 
what  a  bird  is  doing,  —  what  it  is  searching  and  finding  for  food. 
Clear  observation  on  this  point  seldom  fails  to  answer  the 
question,  Why  is  the  bird  here  ? 

Study  with  equal  care  all  the  elements  which  can  account 
for  a  scarcity  of  l)irds  or  the  absence  of  particular  species. 
What  necessities   of  bird   life   are   lacking?    What  natural 


BIRDS 


29 


enemies  of  the  different 
species  are  present  ?  Mucli 
of  this  side  of  the  prob- 
lem will  be  worked  out 
naturally  in  connection 
with  nestuig  habits,  the 
study  of  nest  building, 
and  the  fate  of  the  differ- 
ent nests  in  the  spring. 

Pay  particular  attention 
to  the  bird-food  plants  of 
the  area  with  reference  to 
abundance  of  food  at  dif- 
ferent seasons.  Note  the 
condition  hi  this  respect 
for  the  different  months. 
Is  the  area  stripped  of 
available  food  by  the  time 
robins  and  bluebirds  have 
migrated  in  the  fall  ?  May 
this  help  to  explahi  bird 
migrations  ? 

Note  in  detail  what  pro- 
visions have  been  made  in 
your  district  to  supply  the 
necessaries  of  bird  life, — 
bird  houses,  drinking  and 
bathing  fountams,  plant- 
ing of  food  trees.  AV^hat 
is  done  to  protect  the  birds 
from  enemies  ?  What  in- 
fluence have  these  provi- 
sions exerted  on  the  bird 
population    as    compared 


Fn}.  11.  Bird  fountain.    Natural  rocks  laid 

in  cement  with  deep  chinks  filled  with  soil 

and  planted  with  mosses,  ferns,  and  wild 

flowers 

fhutoinraph  l>y  the  author 


30 


CIVIC  BIOLOGY 


with  neighboring  districts  in  which  no  such  provisions  are 
made  ?  What  is  the  practical  vahie  of  such  work  as  shown 
by  your  account  of  insect  injury  ?  of  losses  caused  by  birds  ? 
Other  important  Imes  of  bird  work  relate  to  destruction  of 
weed  seeds  and  the  control  by  owls,  hawks,  and  slirikes  of  nox- 
ious mammals,  —  mice,  moles,  rats,  gophers,  etc.  Keep  these 
matters  in  mind  throuo^hout  the  year  wliile  doing  the  field  work. 


Fig.  12.  Bird  house  for  study  of  home  life ;  windowpane  is  back  wall  of  house 
Photograph  by  the  author 

The  birds  in  your  district  will  change  during  different  sea- 
sons. During, the  fall  migration  the  "  summer  residents  "  will 
leave  for  the  south,  and  many  species  whose  breeding  range  is 
farther  north  will  migrate  through  the  territory.  These  species 
may  be  designated  as  "transient  visitants."  They  migrate  by 
us  to  the  northward  in  the  spring  and  southward  in  the  fall. 
After  settled  cold  weather  begins  there  will  be  left  the  "  per- 
manent residents,"  —  about  thirty-six  species  for  the  latitude 


BIRDS  31 

of  New  York  (Chapman),  —  and  "  winter  visitants,"  seventeen 
species  of  birds  that  come  from  the  north  and  spend  part  or 
all  the  winter. 

Make  provision  for  the  winter  birds.  Suet  and  a  piece  of 
fat  pork  may  be  tied  to  a  branch  of  a  tree,  with  a  tray  also 
fastened  to  the  trunk,  in  which  seeds  (millet,  corn,  sunflower, 
pumpkin,  or  squash)  and  cracked  nuts  (butternuts  are  espe- 
cially good)  may  be  kept,  and  on  the  ground  close  by  a  pile 
of  chaff  or  loft  sweepings.  The  purpose  of  this  is  to  attract 
all  the  winter  birds  within  range  of  easy  observation.  The 
tray  may  be  attached  to  the  living-room  window  sill,  if  on  the 
south  side  of  the  house,  an  attractive  branch  may  be  fastened 
at  the  side  of  the  window,  and  the  heap  of  chaff  may  be  put 
under  it,  close  to  the  house.  This  latter  must  be  kept  free 
from  snow  through  the  winter. 

The  work  of  the  year  is  intended  to  yield  a  complete  pic- 
ture of  the  life  and  work  of  the  birds  in  your  district.  At 
stated  intervals  your  observations  should  be  carefully  written 
up  under  various  heads.    We  suggest  the  following : 

September  —  My  Bird  Study  Tract  (giving  chart  and  descri[>tions 
of  natural  features). 

October  —  To  what  Extent  do  Birds  prevent  Insect  Depreda- 
tions? 

November  —  The  Fall  Migration  of  Birds. 

December  —  Winter  Provision  for  Birds,  —  Permanent  Residents 
and  Winter  Visitants. 

February  —  The  Work  of  our  Winter  Birds. 

March  —  My  Plans  for  Bird  Work  this  Spring. 

April  —  Birds'  Nests ;  Nest  Building  ;  Nesting  Sites  of  Different 
Species ;   Materials. 

May  —  Bird  Songs  and  Notes,  and  what  they  mean. 

May  —  Feeding  Habits  of  Birds. 

May  —  My  Observations  on  Feeding  of  Young;  Amount  of  Insect 
Food. 

June  —  Summary  and  Results  of  my  Bird  Study  for  the  Year. 


32  CIVIC  BIOLOGY 

Other  more  general  topics,  like  the  following,  are  suitable  as 
assisfnments  for  different  members  of  the  class  to  work  out  and 
report  upon  toward  the  close  of  the  year : 

The  English  Sparrow  in  the  Locality may  be  subdivided  into :  Ke- 

latious  to  Native  Birds  ;  Damage  caused  by ;  Methods  of  Extermination. 

The  Life  and  Work  of  the  Bluebird.  (Substitute  the  name  of  any 
other  common  bird,  if  desired.  It  w^ould  be  well  if  each  member  of  the 
class  could  devote  special  attention  to  working  up  the  life  t)f  some 
important  species.) 

By  a  free  interchange  of  notes  these  reports  may  be  made 
more  complete,  and  in  this  way  each  is  made  the  summary  of 
the  work  of  the  whole  class  upon  the  topic.  We  may  vary  and 
enliven  tlie  reports  by  casthig  them  in  the  form  of  debates 
about  bird  problems  that  are  in  dispute  in  the  neighborhood. 
For  example : 

Resolved,  that  the  robin  merits  ])rotection.    (Substitute  other  birds.) 

Resolved,  that  the  crow  should  be  exterminated. 

Resolved,  that  there  should  l)e  a  bounty  on  hawks  and  owls. 

Resolved,  that  the  bobwhite  should  l)e  placed  on  the  protected  list  for 
a  period  of  ten  years. 

Resolved,  that  spring  shooting  of  waterfowl  ought  to  be  prohibited 
by  law  in  all  states. 

Resolved,  that  active  measures  be  taken  to  establish  a  preserve  for 
the  breeding  of  grouse  and  waterfowl  in  this  township. 

Resolved,  that  it  is  better  policy  to  preserve  native  s[)ecies  than  to 
import  grouse  from  other  countries. 

Resolved,  that  the  killing  of  song  and  insectivorous  birds  f(^r  milli- 
nery purposes  is  legitimate. 

Resolved,  that  a  person  who  allows  his  cats  to  kill  birds  should  be 
subject  to  the  same  fine  as  if  he  killed  them  himself. 

Resolved,  that  a  law  be  passed  making  owners  of  cats  responsible  for 
the  birds  they  kill. 

Resolved,  that  it  is  an  unwarranted  waste  of  bird  life  to  make  ^^^ 
collections. 

This  list  might  be  extended  indefinitely. 
Birds  are  divided  popularly  into  "  soft-billed,"  eating  mainly 
worms,  insects,  and  berries ;  and  "  hard-billed,"  feeding  upon 


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34  '      CIVIC  BIOLOGY 

seeds.  Both  classes,  however,  feed  the  young  mainly  on  in- 
sects. Our  gardens,  fields,  and  roadsides  are  weedy  enough, 
but  who  can  imagine  what  they  would  be,  were  not  thousands 
of  tons  of  weed  seeds  destroyed  annually  by  the  sparrows, 
bobwhites,  doves,  larks,  blackbirds,  and  others.  About  fifty 
species  of  birds  are  efficient  weed  destroyers.  Compare  and 
draw  a  few  typical  hard  and  soft  bills  to  fix  this  distinction. 
Beal  has  estimated  that  the  tree  sparrows  alone  in  the  state  of 
Iowa  destroy  annually  about  875  tons  of  weed  seed.  Are  both 
weeds  and  seed-eating  birds  abundant  in  your  bird  tract  ? 

Hawks,  owls,  and  shrikes  render  service  in  destroying  noxious 
mammals.  Are  the  mice,  rats,  field-mice,  or  gophers  numerous 
in  your  district,  and  what  amount  of  damage  do  they  cause 
by  eating  grain  or  girdling  trees  ?  Dr.  C.  Hart  Merriam  has 
estimated  that  a  bounty  act. on  hawks  and  owls,  during  its 
operation  in  Pennsylvania  for  a  year  and  a  half,  cost  the  state 
not  less  than  $4,000,000. 

The  accompanying  food  chart  shows  about  all  we  know  of 
the  foods  of  many  of  our  commonest  species.  The  blank 
squares  in  the  chart  indicate  generally  deficiencies  in  observa- 
tion, and  not  that  any  particular  bird  does  not  eat  any  par- 
ticular insect ;  hence  they  are  in  reality  the  most  interesting 
part  of  the  chart  because  they  suggest  further  study.  Observe 
the  birds  in  your  district,  or,  if  you  have  a  young  or  disabled 
bird,  make  definite  feeding  tests  and  record  the  results  in  your 
food  chart.  The  chart  will  thus  enable  you  to  feed  intelligently 
many  birds  that  come  to  hand,  and  also  to  add  to  our  knowl- 
edge of  the  subject.  The  probable  diet  of  any  bird  not  named 
on  the  chart  may  be  judged  from  that  of  its  near  relatives.^ 

1  The  authors  would  ■  be  grateful  if  those  who  make  such  feeding  tests 
would  send  them  any  data  secured. 


CHAPTER  V 
METHODS  OF  BIRD  STUDY  AND  SPECIAL  PROBLEMS 

I  have  no  doubt,  therefore,  that  the  wild  pigeon  is  still  with  us,  and  that 
if  protected  we  may  yet  see  them  in  something  like  their  numbers  of  thirty 
years  ago.  —  John  Burroughs,  1906 

In  order  to  do  the  work  outlined  in  the  last  chapter  we 
must  know  the  birds.  It  is  supposed  that  practical  acquaint- 
ance with  the  commoner  species  has  been  begun  in  the  nature 
study  of  the  grades.  The  present  course  is  planned  as  an  "  ad- 
vanced," and,  so  far  as  school  life  is  concerned,  a  final  year  of 
bird  study,  which  shall  organize  and  complete  previous  knowl- 
edge, work  out  more  thoroughly  as  practical  problems  the 
values  and  uses  of  different  species,  and  help  to  answer  the 
question,  '^  How  may  a  community  make  the  most  of  its  bird 
life  ?  "  If  we  are  to  have  intelligent  progress,  every  one  must 
know  these  things,  because  the  ignorance  of  one  may  vitiate 
the  best  efforts  of  a  community. 

After  completing  plans  for  individual  bird-study  tracts,  dis- 
cuss in  the  class  what  species  merit  a  place  in  the  year's 
course.  Each  member  may  present  a  list  including  his  choices, 
and  from  these  the  official  list  for  the  year  may  be  selected. 
The  lists  should  be  changed  somewhat  from  year  to  year, 'as 
conditions  change  and  emphasis  is  shifted  from  one  to  another 
group  of  problems. 

In  this  connection,  as  well  as  in  the  general  problem  of 
organizing  our  knowledge  of  birds,  scientific  classification  is 
of  great  assistance.  Scientific  books  have  described  for  the 
world  12,500  species  of  birds,  and  of  this  number  768  belong 
to  North  America.    This  large  number  of  species  means  that 

35 


•r      t-    c 


^1 


M  ^      X 


Ph     -^ 


If 


-  y. 


?A\ 


METHODS  OF  BIRD  STUDY 


37 


biixls  have  become  differentiated  to  fit  all  sorts  of  envii'ounieiits, 
—  air,  water,  marsh,  prairie,  and  forest.  Those  of  similar  activi- 
ties, like  machines  built  and  adjusted  to  their  work,  have  come 
to  have  similar  structures,  —  of  body,  Aving,  foot,  and  bill. 
Discovery  of  these  adjustments  will  add  fresh  interest  at  every 
turn  and  mcrease  respect  for  scientific  bird  study.  Fig.  8  is 
designed  to  fix  in  mind  the  fundamental  relations  of  the  dif- 
ferent orders  to  environment.    Common  names  often  vary  in 


Primaries 


Primary  Covert 
Greater  (-averts 
Middle  Coverts 
Lesser  Coverts 
ilnla  or  Spurious  Wing 
Crown 
Median  Line-^ 
Mandihles{2^r 

Lore 
SuperclUary  Line 
Ear  Coverts  or  Atiriculars 


Tail  Coverts 

Rump 

Back 


Scapulars 
Wing  Bars 
Shoulder 
Tibia 
Tarsus 


Vi(..  l.').    Topography  of  a  bird 
C.  A.  Reed 

different  parts  of  the  same  country.  Scientific  names  are  the 
same  for  all  languages  the  world  over,  and  this  is  the  time  to 
learn  them,  if  they  are  ever  to  be  remembered. 

Again,  in  order  to  describe  birds  quickly  and  accurately  — 
and  as  a  help  to  seeing  them  properly  —  we  must  learn  to 
name  the  external  parts,  the  so-called  "  topography  "  of  a  bird. 
The  terms  in  Fig.  15  are,  in  the  main,  self-explanatory.  The 
"  primaries,"  "  secondaries,"  and  "  tertials  "  are  attached  respec 
tively  to  the  hand,  fore-arm,  and  upper-arm  bones  of  the  wing. 

The  following  list,  suited  to  central  New  England,  is  given 
merely  by  way  of  suggestion,  as  if  the  writer  were  a  member 


38  CIVIC  BIOLOGY 

of  the  class.  Several  species  not  now  found  in  the  territory 
are  included  because  they  are  related  to  problems  which  every 
intelligent  member  of  the  nation  ought  to  be  helping  to  solve. 
Order  Pygopodes  ("rump-footed")  —  diving  birds.  The  birds 
of  this  group  enliven  our  waters,  and  the  loons  give  us  some 
weird  music.  While  anglers  may  object  to  sharing  the  fish 
with  them,  the  main  question  is  whether  we  prefer  to  see 
them  on  our  ponds  and  lakes  or  on  the  ladies'  hats.  The  two 
common  species  within  our  territory  are : 

Pied-billed  grebe  —  Podilymhus  pddiceps. 
Loon ;  great  northern  diver  —  Gdcia  imber. 

Order  Longipennes  ("  long- winged  ")  —  gulls,  terns,  etc.  The 
gulls  and  terns  have  required  active  protection  in  recent 
years  to  prevent  their  extermination  by  the  egglers  and  plume 
hunters.  What  would  our  seascapes  be  without  them?  The 
protection  which  has  been  accorded  these  birds  is  one  of  the 
most  encouraging  signs  that  values  other  than  mercenary  are 
beginning  to  be  appreciated.  Aside  from  their  beauty,  these 
birds  are  much-needed  scavengers  of  our  harbors  and  coasts, 
and  .the  inland  species  are  most  efficient  destroyers  of  insects. 
Two  common  types  are : 

Herring  gull  —  Ldrus  argentdtus. 
Common  tern  —  Sterna  hirundo. 

Order  Anseres  (anser,  "  a  goose  ")  —  ducks,  geese,  swans.  The 
problem  of  our  waterfowl  is  nearing  its  final  stage.  ^  The  vast 
breeding  grounds  in  the  Northwest  are  now  open  to  sports- 
men and  settlers,  and  when  the  wild  fowl  have  been  extermi- 
nated from  these,  as  they  have  been  from  their  more  southern 
ranges,  the  work  of  destruction  will  be  complete  and  final. 
It  is  high  time  this  is  appreciated  as  a  national  problem,  and 
effective  measures  taken  toward  its  solution.    The  first  step, 

1  See  H.  K.  Job,  Country  Life  in  America,  April,  1906. 


METHODS  OF  BIKD  STUDY  39 

it  seems  clear,  should  be  total  prohibition  of  spring  shooting 
from  Florida,  the  Gulf,  and  Mexico  to  the  Arctic  Ocean. 

Next,  we  should  offer,  for  a  period  of  years  at  least,  com- 
plete protection  and  every  inducement  for  all  birds  of  this 
order  to  breed  throughout  the  United  States,  wherever  a  pond, 
marsh,  or  lake  can  be  guaranteed  as  a  safe  and  permanent 
"  preserve."  All  kinds  of  waterfowl  quickly  learn  where  they 
are  safe,  and  if  unmolested  become  tame  and  breed  in  great 
numbers  even  in  small  ponds.  Is  there  a  chance  for  a  preserve 
in  the  neighborhood  ?  The  wood  duck  is  already  on  the  verge 
of  extinction  and  should  be  absolutely  protected  in  every 
state.  Nests  discovered  in  the  neighborhood  should  be  guarded 
from  disturbance.  In  New  England,  for  a  term  of  years,  let  the 
broods  go  unmolested  even  in  open  season  on  the  chance  that 
more  may  return  to  breed  the  followmg  spring.  On  the  mur- 
derous and  stupid  prmciple,  ^'  If  I  don't  shoot  it,  some  one 
else  will,"  the  last  wood  duck  will  fall  to  the  ground  and  the 
race  of  our  most  exquisite  waterfowl  be  extinct.  Extermina- 
tion of  a  valuable  species  is  not  only  a  national  calamity,  but 
a  national  crime,  —  a  piece  of  monumental  stupidity  and  folly 
as  well.  Let  us  change  the  above  principle  to  read,  "If  I 
have  the  decency  and  sense  to  spare,  some  one  else  may."  To 
the  problem  of  increasing  and  protecting  our  waterfowl  and 
reestablishing  them  throughout  their  native  breeding  ranges 
should  be  brought  the  best  energies  of  the  class.  All  members 
of  the  order  should  be  considered  in  the  light  gained  from  a 
study  of  the  following  types : 

Wood  duck  —  A  ix  spdnsa.  Mallard  duck  —  .4  nas  platyrhynchos. 

Pintail  —  Ddjila  acuta.  Whistling  swan —  Olor  columhidnus. 

Canada  goose — Brdnta  canadensis.     Trumpeter  swan — Olor  huccuvdtor. 

Order  Herodiones  {herodios^  "  a  heron  ")  —  herons,  storks,  etc. 

These  birds  of  our  marshes  and  swamps  are  mainly  of  aesthetic 
interest  and  value,  and  although  they  eat  a  few  fishes,  frogs,  and 


40  CIVIC  BIOLOGY 

snakes,  they  are,  on  account  of  this  value,  accorded  the  protec- 
tion of  the  law  in  Massachusetts.    As  examples  we  may  take : 

Night  heron  —  Nycticorax  mevius  —  a  generally  common  species. 

Snowy  egret  —  Egi-etta  candid issima  —  a  Southern  species,  but  one 
which  ought  to  be  known  to  every  American  Xorth  and  South,  in 
order  to  save  it  from  extermination  by  the  milliners. 

Order  Limicola  (limus,  "mud";  colercy  "to  dwell")  —  shore 
birds.  Many  of  these  birds  of  our  marshes  and  muddy  shores, 
wet  brook  beds,  and  upland  pastures,  merit  protection  on  ac- 
count of  their  valuable  service  as  insect  destroyers,  and  also 
because  of  the  imminent  danger  of  extermination  in  which 
several  of  the  best  species  stand.  The  argument  given  for  the 
wood  duck  applies  with  more  than  double  force  to  the  wood- 
cock, because  the  former  produces  from  eight  to  fourteen  eggs 
to  the  woodcock's  four.  The  same  preserves  would  serve  for 
the  waterfowl  and  shore  bu-ds  as  well.  Several  of  the  plover  are 
in  great  need  of  protection,  but  the  five  species  that  follow 
are  possibly  all  we  can  begin  with,  and  will  serve  to  illustrate 
the  problems  of  the  group: 

Woodcock — Phildhela  mi7ior.  Spotted  sandpiper — Actitls  maculdria. 

Wilson  snipe —  Gallindgo  delicdta.    Eskimo  curlew  —  Numenius  horedtis. 

(iolden  plover —  Charddrius  dominicm. 

Order  Gallina  (gallus,  "a  cock")  —  grouse,  pheasants.  The 
problem  in  regard  to  all  the  birds  of  this  order  is  again  that  of 
protectmg  those  that  remain,  and  of  reestablishing  in  their 
original  ranges  such  species  as  have  already  been  exterminated 
from  certain  regions.  Were  it  not  for  stray  and  uncontrolled 
cats  we  could  make  town  and  city  parks  —  in  fact,  the  limits 
of  all  villages,  towns,  and  even  cities  —  preserves  for  grouse 
and  waterfowl.  We  could  in  this  way  place  them  where  the 
greatest  number  might  enjoy  seeing  and  hearing  them ;  while 
a  constant  supply  would  overflow  the  preserve  limits  for  our 
sportsmen.  Special  problems  occur  with  each  of  the  five  follow- 
ing types  suggested  for  study. 


Fir..  16.  Ruffed  grouse  cock  strutting 


Fig.  17.  Bobwhite  cock  caring  for  brood  of  fifteen  chicks  which  he 

incubated  and  hatched 

Photograph  by  the  author 

41 


42 


CIVIC  BIOLOGY 


Bobwhite  —  CoUnus  virginidnus.  This  species,  if  sufficiently  abun- 
dant, could  probably  become  our  most  important  insect-  and  weed-seed- 
destroying  ground  bird  for  garden  and  field.  The  crop  of  one  bird 
contained  101  potato  beetles,  another  two  table  spoonfuls  of  chinch 
bugs,  and  another  15,000  weed  seeds.  Winter  protection  and  feeding 
is  another  problem  which  should  receive  attention. 

Ruffed  grouse  —  Bondsa  umbellus.    Wherever  at  all  scarce,  this  finest 

of  our  game  birds  should  be  provided 
with  safe  covers  which  will  insure 
its  increase  in  the  locality. 

Heath  hen — Tympanuchus  cupido. 
This  species  presents  the  problem  of 
a  numerous  and  valuable  game  bird, 
once  generally  distributed  over  New 
England  and  now  reduced  to  a  few 
pair  confined  to  the  oak  barrens  of 
Marthas  Vineyard.  It  is  a  slightly 
variant  woods  form  of  the  Western 
i^rairie  chicken,  which  is  rapidly 
being  exterminated  from  the  Missis- 
sippi Valley.  Every  effort  should  be 
made  to  save  this  remnant,  and  with 
it  restock  the  mainland  under  condi- 
tions which  shall  insure  the  heath 
hen's  regaining  its  original  range. 

Mongolian  or  ring-necked  pheas- 
ant—  Phasidnus  torqudtus.  This  is 
an  introduced  species,  concerning  the 
value  of  which  there  is  much  ques- 
tion at  present. 

Wild  turkey  — -  Meledgris  gallopdvo.  As  far  as  New  England  is  con- 
cerned we  must  write  the  word  "  exterminated  "  after  the  name  of  this 
our  largest  game  bird.  By  concerted  action,  and  with  a  suitable  game 
preserve,  might  the  wild  turkey  not  be  reintroduced  ?  Would  it  not  be 
worth  while  ? 


Fig.  18.  Ruffed  grouse  cock 

drumming 

Photograph  by  the  author 


Order  Columba  (columboy  "a  dove").  The  pigeons  and  doves 
the  world  over  are  among  our  most  valuable  food  and  game 
birds.  The  dodo  of  Mauritius  and  the  solitaire  of  Rodriguez 
were  gigantic  ground  pigeons  as  large  as  swans,  but  with  wings 


METHODS  OF  BIRD  STUDY 


43 


too  small  for  flight.  The  last  record  of  the  dodo  was  in  1681. 
Both  of  these  remarkable  species  were  unwittingly  extermi- 
nated by  the  introduction  into  the  islands  of  hogs,  which  de- 
stroyed their  eggs  and  young. 

There  are  in  North  America  ten  genera  and  seventeen 
species  and  varieties  of  pigeons  and  doves.  Most  of  these  are 
Western  and  Southern.  The  two  named  below  suggest  most 
important  problems  for  eastern  North  America.    For  the  Rocky 


w        ^P 

Fig.  19.  Egg  of  passenger  pigeon,  on  black  velvet,  in  nest  of  mourning  dove 

The  pigeon  laid  only  one  ^g^,  about  \\  inches  long;  the  dove,  two  eggs  about 
1  inch  long.  This  figure  thus  furnishes  a  decisive  means  of  distinguishing  the  two 
species.  Photograph  from  specimens  in  the  American  Museum  of  Natural  History 

Mountain  and  Pacific  States  the  types  studied  should  be  the 
band-tailed  pigeon,  ColUmha  fascidta,  from  British  Columbia 
to  Mexico;  Viosca's  pigeon,  C.f.  vidscce,  southern  Lower  Cali- 
fornia ;  and  the  red-billed  pigeon,  C.  flavirdstris. 

Passenger  pigeon  —  Ectopisies  migratorius.  This  most  valuable  of 
North  American  pigeons  existed  less  than  forty  years  ago  in  flocks 
which  stretched  from  horizon  to  horizon.  It  is  now  a  serious  question 
wkether  the  last  living  specimen  has  not  been  seen. 


44 


CIVIC  BIOLOCIY 


(For  three  years  past  rewards  aggregating  over  |oOOO  for  discovery 
and  report  of  undisturbed  nesting  pairs  or  colonies  of  passenger  pigeons, 
anywhere  in  Xorth  America,  have  remained  unclaimed,  and  no  tangible 
evidence  has  been  received  of  pigeons  killed  or  even  seen  during  this 
time.  This  is  commonly  accepted  as  proving  the  species  extinct  in  the 
wild  state.  One  old  bird  still  survives  in  the  Cincinnati  Zoological  Gar- 
den. If  nesting  pigeons  are  ever  found,  they  should  he  most  carefully 
safeguarded,  and  all  protective  agencies,  private,  state,  and  national,  bo 

focused  on  their  jn-eservation 
and  increase.) 

Mourning  dove  —  Zenai- 
diira  macroura  caroline/isii<. 
Every  effort  is  now  being 
made  to  save  this  species  in 
New  England.  It  is  abun- 
dant in  the  South  and  Afiddle 
West. 

Order  Raptores  {raptor^ 
"  a  robber  ")  —  hawks, 
eagles,  owls.  The  luiwks 
and  owls  furnish  perhaps 
the  most  complicated  and 
difficult  problem  con- 
nected with  our  bird  life. 
By  many  of  the  best  authorities  the  majority  are  accounted 
among  our  most  valuable  birds,  on  account  of  the  great  num- 
bers of  noxious  mammals  —  field  mice,  gophers,  rats,  etc. — 
which  they  destroy.  Most  of  the  hawks,  too,  feed  largely  on 
insects  when  they  are  abundant,  and  take  comparatively^  few 
birds,  either  tame  or  wild.  In  determinmg  the  value  of  birds 
in  this  class,  however,  it  is  always  an  open  question  whether 
the  few  insectivorous  birds,  —  which  may  form  only  1  or  2  per 
cent  of  the  hawk's  total  food,  —  if  allowed  to  live,  might  not 
have  done  much  more  valuable  work  than  the  sum  total  of  the 
predacious  species.  We  must  leave  questions  of  this  kind  to 
be  worked  out  from  practical  experience  and  observation. 


Fit;.  20.  Y(^uiiii'  red-shouldered  hawks 


METHODS  OF  BIRD  STUDY  45 

When  depredations  on  the  poultry  yard  or  disturbance 
among  small  birds  is  marked,  it  is  all  but  certain  that  either  a 
sliarp-shinned  or  a  Cooper's  hawk  is  causing  all  the  mischief, 
lliese  two,  of  the  commoner  hawks,  feed  almost  exclusively 
on  other  birds  and  bring  practically  all  the  popular  ill-repute 
upon. the  rest  of  the  family.  In  addition  to  these,  the  Amer- 
ican goshawk,  a  Canadian  species  which  enters  the  Northern 
States  in  winter,  feeds  largely  on  game  and  poultry ;  and  the 
rarer  duck  hawk,  seldom  seen  far  from  the  coast  or  larger 
waterways,  feeds  chiefly  on  waterfowl. 

Some  authorities  are  inclined  to  mahitain  that  the  smaller 
species,  sparrow  and  pigeon  hawks,  may  prove  useful  in  towns 
and  cities  in  destroying  English  sparrows.  This  is  a  good 
problem  to  assign,  if  some  of  these  bii-ds  are  known  to  nest 
in  the  neighborhood,  in  the  only  case  known  to  the  author  a 
pair  of  sparrow  hawks  which  nested  on  one  of  the  buildings 
of  the  Worcester  Polytechnic  Institute  had  finally  to  be  shot 
on  account  of  serious  inroads  upon  the  valuable  bird  life  of 
the  campus.    Common  types  are  : 

Marsh  hawk —  Circus  liudsoulus. 

Sharp-shinned  hawk  —  Accipiter  relox. 

Cooper's  hawk  —  Accipiter  coopcrL 

American  goshawk  —  Astur  afrlcajnllus. 

Red-tailed  hawk  —  Biiteo  horedlis. 

Red-shouldered  hawk  —  Buteo  linedtus. 

Bald  eagle  —  Haliceetus  leucocephalus. 

Duck  hawk  —  Fdlco  peregrinus  dnatum. 

Pigeon  hawk  —  Fdlco  cohimbdrlus. 

Sparrow^  hawk  —  Fdlco  sparve'rhis. 

American  osprey,  or  fish  hawk  —  Pandion  halidctus  carolinentn's. 

Screech  owl  —  Ottis  dsio. 

Great  horned  owl  —  Bubo  virginidnus. 

Order  Cocq/ges  (cocq/Xy  "a  cuckoo").  These  are  among  our 
most  valuable  birds  as  destroyers  of  hairy  caterpillars,  and  on 


46 


CIVIC  BIOLOGY 


this  account  they  should  be  universally  protected.    The  order 
contains  the  cuckoos  and  kingfishers.  Types  are : 

Yellow-billed  cuckoo  —  Coccyzus  americdnus. 

Black-billed  cuckoo  —  Coccyzus  erytlirophthdlmus. 

Belted  kingfisher  —  Ceryle  dlcyon.    This  is  an  interesting  bird,  and 

we  need  not  generally  be- 
grudge it  the  minnows  which 
it  takes.  About  fish  hatcher- 
ies and  trout  streams,  how- 
ever, it  is  in  general  disfavor. 

Order  Pici  (picusy  "  a 
woodpecker ' ') .  The  wood- 
peckers are  in  general  of 
great  value  as  destroyers 
of  orchard  and  forest  in- 
sects. The  sapsucker  is 
generally  considered  an 
in jurious  bird,  and  should 
be  clearly  distinguished 
from  the  valuable  spe- 
cies which  it  resembles, 

and  which  may  sometimes  visit  its  sap  holes.    We  should 

study  the  following  common  species: 

Hairy  woodj)ecker  —  DrydOates  villdsus. 

Downy  woodpecker  —  Dryobates  puhescens. 

Sapsucker — Sphyj-apicus  vdrius. 

Red-headed  woodpecker  —  Melane'rpes  erythrocephalus. 

Flicker —  Coldptes  aurdtus. 

Order  Macrochires  (makrosy  "long";  cheiry  "hand").  The  first 
three  of  the  types  given  below  are  among  our  most  valuable 
insectivorous  birds,  catching,  as  they  do,  both  day-  and  night- 
flying  insects.  The  humming  bird  feeds  upon  minute  insects 
and  spiders,  and  also  largely  upon  the  nectar  of  flowers  and 
the  sap  of  trees  (from  the  holes  of  sapsuckers).    It  is  most 


Fig.  21.   Ruby-throat,  nest  and  young 
Photograph  by  E.  E.  Evans 


METHODS  OF  BIRD  STUDY 


47 


easily  tamed,  and  may  be  fed  on  honey  and  water,  half  and  half, 
with  plant  lice  and  spiders.    All  should  be  familiar  with  the : 

Whippoorwill  —  A  ntrostomus  vociferus. 
Nighthawk  —  Chordeiles  virginidnus. 
Chimney  swift —  Chcetura  peldgica. 
Ruby-throated  humming  bird  —  Archilochus  cdlubris. 

Order  Passeres  {passer,  "  a  sparrow  ") — perching  birds.  In  this 
largest  order,  which  contains  more  than  half  the  species  to  be 
studied,  the  family  names  will  be  of  assistance  in  distinguish- 
mg  the  various  groups. 

Family  Tyrannidcs. —  flycatchers.    Types: 

Kingbird  —  Tyrdnnus  tyrdnnus. 
Crested  flycatcher  —  Myidrchus  crinitus. 
Phcebe  —  Saydrnis  phwbe. 
Wood  pewee  —  Myidchanes  virens. 
Least  flycatcher  —  Empiddnax  minimus. 

Almost  the  entire  food  of  this  group,  as  the  name  indicates,  is 
insects,  and  stomach  examinations  have  proved  that  the  insects  taken 
are  mainly  injurious.  From  the  common  habit  of  v^^atching  from  a 
conspicuous  perch  and  flitting 
out  to  catch  insects  as  they 
pass,  the  flycatchers  are  most 
interesting  birds  to  study,espe- 
cially  in  ascertaining  exactly 
hovr  many  insects  a  bird  may 
catch  within  a  given  time,  A 
laboratory  period  devoted  to 
such  work  will  instill  a  higher 
appreciation  of  the  value  of 
bird  life  than  will  any  other 
lesson  in  the  course. 

The  only  question  as  to 
the  value  of  the  group  refers 
to  the  kingbird  and  its  de- 
struction of  the  honeybees.  While  few  bees  have  been  found  in  its 
stomach,  and  it  was  therefore  acquitted  of  serious  injury,  hundreds  of 
crushed  bees  have  since  been  discovered  under  its  favorite  perches,  when 


Fig.  22.  Chipping  sparrow  feeding  young 
cowbird 


48 


CIVIC  BIOLOGY 


these  are  near  the  hives.    This  is  a  good  problem  to  have  thoroughly 
worked  up  in  any  neighborhood  in  which  bees  are  kept. 

Family  AlaudidcR   {alauda,  "a  lark  ")— larks.    Horned  lark  —  Otdco- 
ris  alpestn'a.    For  open  fields  and  prairies  this  is  a  valuable  bird,  as  it 

eats   great  quantities  of  weed 
seeds  and  insects. 

Family  Corvid<E  (corvus,  "a 
crow")  —  crows,  jays,  American 
magpie.  Blue  jay  —  Ct/anocitfa 
cristdta.  This  bird  has  an  odious 
reputation  for  robbing  other 
birds  of  their  eggs  and  young. 
Study  the  bird  for  yourself,  and 
before  inflicting  cajntal  ]>unish- 
luent  decide  whether  the  jay  is 
good  or  bad  for  the  locality. 

American  crow  —  Cdrvus 
hrachyvhijnchos.  The  worst  crime 
of  the  crow  is  also  nest  robbing. 
(I  have  known  a  pair  to  empty 
two  robins'  nests  of  seven  young 
as  a  single,  perhaps  partial, 
breakfast.) 

Family /cter/^cE  (icteros,  "a  yel- 
low bird  ")  —  blackbirds,  orioles, 
etc.  Cowbird — Molothrus  dter. 
This  bird  is  a  parasite  and  com- 
pels other  species,  generally 
warblers,  vireos,  and  sparrows, 
smaller  than  itself,  to  brood  and 
rear  its  young  at  the  expense 
of  their  own.     Cowbirds'  eggs 


Fig.   23.     Junco's   nest   in  the   aviary 

of     Mr.    Herbert     Parker,     Lancaster, 

Massachusetts 


should  be  removed  from  the  nests  of  other  birds  whenever  found. 

Bobolink  —  Dolichdnyx  oryzivorus.  In  the  N^orth  this  bird  is  appre- 
ciated as  one  of  our  most  fascinating  meadow  songsters,  if  it  is,  not  at 
the  head  of  the  list.    In  the  South  it  is  the  destructive  ricebird. 

Bronzed  grackle  —  Quiscalus  quiscula  cfneus. 
Red-winged  blackbird  —  Ageldius  phceniceus. 
Meadow  lark  —  Sturnella  magna. 
Baltimore  oriole  —  fcterus  gdlhula. 


METHODS  OF  BIKD  STUDY  49 

Family  Fringillidce,  (fringilla,  "a  finch") — sparrows,  finches.    Types: 

Purple  finch  —  Cnrpodacus  purjnireus. 

American  goldfinch  —  Astragalinus  tristis. 

English  sparrow  —  Passer  domesticus. 

White-throated  sparrow  —  Zonotrichia  nlhico/lis. 

Tree  sparrow  —  Spizella  monticola. 

Chipping  sparrow  —  Spizella passcrinn. 

Junco  —  Junco  hyemdlis. 

Song  sparrow  —  Melospiza  melodUi. 

Fox  sparrow  —  Passerella  iliaca. 

Towhee,  chewink  —  Pipilo  ert/throphthdlnnis. 

Kose-breasted  grosbeak  —  Zamelddia  hidovicidmi. 

Indigo  bunting  —  Passfrina  cijdnea. 

The  problems  in  this  group  are  the  valuable  service  rendered  by  all 
the  sparrows  in  weed-seed  destruction;  and,  also,  the  damage  caused 
by  the  English  sparrow.  A  single  observation  of  the  killing  of  a  tree 
swallow  or  a  bluebird  by  sparrows,  or  their  eating  the  eggs  from  a  rob- 
in's nest,  is  usually  enough  to  convince  a  person  of  the  advisal>ility  of 
ridding  the  neighborhood  of  these  pests.  The  year  after  all  agree,  the 
English  sparrow  may  be  banished  from  the  continent  into  which  it  was 
so  foolishly  introduced  in  1851.  Until  all  agree,  not  much  headway  can 
be  made  against  a  species  that  has  the  })Ower  to  increase  from  a  single 
pair  to  275,716,983,698  in  ten  years. 

Family  Tanagridtz  —  the  tanagers.  The  scarlet  tanager —  Pirdnga  eri/- 
thromflm.  Why  are  not  these  beautiful  ))irds  more  numerous  in  your 
locality  ? 

Family  Hirundinida  —  swallows  and  martins.  Few  more  efficient,  and 
certainly  no  more  agTeeal)le,  insect  traps  exist  than  the  swallows.  They 
should  all  be  protected  until  they  increase  up  to  the  limit  of  their  insect 
food.  The  purple  martin  and  tree  swallow  nest  preferably  in  l)ird  houses, 
and  provision  about  barns  should  not  be  lacking  for  the  cliff  and  barn 
swallows.  Differences  in  nesting  habits  in  species  so  closely  related  are 
of  general  interest.    Types  : 

Purple  martin  —  Prdgne  siibis. 

Cliff,  or  eaves,  swallow  —  Petrochelidon  lunifrons. 

Barn  swallow  —  Hiriuido  erythrogdstra. 

Tree  swallow  —  Iridoprocne  Inrolor. 

Bank  swallow  —  Ripdria  ripdria. 


50 


CIVIC  BIOLOGY 


Family  AmpelidcE  (ampelus,  "a  vine")  —  waxwings.  The  cedar  wax- 
wing,  BombycUla  ccdrdrum,  known  also  as  the  cherry  bird,  is  noted  for 

destruction  of  cankerworms 
in  our  orchards. 

Family  Laniidce  (lanius, 
"  butcher  ")  —  shrikes.  'Ilie 
loggerhead  shrike,  Ldnius  lu- 
davicidnus,  frequents  hedge- 
rows and  borders  of  fields, 
where  it  feeds  upon  insects, 
field  mice,  and  small  birds. 
In  cities  it  is  said  to  be  of 
some  use  in  destroying  Eng- 
lish sparrows.  Study  the  prob- 
lem in  your  own  locality.  The 
number  of  our  most  valuable 
small  birds  —  chickadees  and 
wrens  —  which  the  shrike 
kills  places  it  decidedly  on 
the  questionable  list. 

Family  Vireonidce.  (vireo, 
"  a  greenfinch  ")  —  the  vireos 
or  greenlets.  These  birds  of 
the  terminal  foliage  and  pen- 
sile nests  are  among  the  best 
of  our  orchard  and  roadside  insect  police.  We  may  certainly  make  the 
acquaintance  of  at  least  three  of  the  seven  common  species. 

Red-eyed  vireo  —  Vireosylva  oUudcea. 
Warbling  vireo  —  Vireosylva  gilva. 
Yellow-throated  vireo  —  Lanivireo  Jldcifrons. 

Family  Mniotiltida  (mnion,  "moss";  tiltos,  "pulled  out")  —  warblers. 
To  make  the  first  acquaintance  with  this  interesting  and  difficult  family 
we  may  begin  with  four  of  the  common  resident  species. 

Black-and-white  warbler  —  Mniotilta  vdria. 
Yellow  warbler  —  Dendroica  cestiva. 
Ovenbird  —  Scurus  aurocapillus. 
American  redstart  —  Setdphaga  ruticilla. 

Family  Troglodytida  {troglodyta,  "cave  dweller")  —  thrashers,  wrens, 
etc.   Mocking  bird  — Mimus  polygldttos.   This  offers  the  problem  of  a  rare 


Fig.  24.    Kemains  of  chickadee  killed  by 
a  shrike 

Photograph  by  the  author 


METHODS  OF  BIRD  STUDY  51 

bird  for  our  district,  and  one  which  is  becoming  rarer  year  by  year.  The 
reason  is  largely  that  specimens  are  desired  for  collections.  Hence  rec- 
ords commonly  read  :  "  Remarkable  instance  of  a  pair  of  mocking  birds 
nesting  in  central  Massachusetts.  On  June  8  both  parents  with  nest  and 
clutch  of  six  eggs  were  collected  and  are  now  in  . . ."  etc.  The  mocking 
bird  is  often  described  as  the  most  remarkable  bird  musician  in  the 
world,  and  we  could  certainly  not  do  less  than  encourage  it  to  breed  as 
far  north  as  possible. 

Catbird  —  Dumetdlla  carolinensis. 

Brown  thrasher  —  Toxdstoma  rufum.  Both  of  these  birds  are  valuable 
to  control  insects  of  garden  and  orchard,  and,  besides,  are  among  our  best 
musicians. 

House  wren —  Troglodytes  aedon.  Every  garden  should  be  well  stocked 
with  this  tireless  insect  destroyer. 

Marsh  wren,  short-billed —  Cistothorus  stelldris.  Compare  with  house 
wren  for  habitat,  foods,  nests. 

Family  Certhiidoi —  creepers.  Brown  creeper  —  Certhia  familidris  ameri- 
cdna.  One  of  our  winter  birds  that  should  be  generally  known  and  pro- 
tected. 

Family  Paridcs — nuthatches  and  titmice.  White-breasted  nuthatch  — 
Sitta  carolinensis. 

Chickadee  —  Pentliestes  atricapillus.  All  are  agreed  that  the  chickadee 
is  one  of  the  most  useful  birds  in  freeing  orchards  of  all  sorts  of  insect 
pests,  from  cankerworms  to  aj)hides. 

Family  Sylviida  —  kinglets,  gnat  catchers,  etc.  The  ruby-crowned  king- 
let —  Regulus  sdtrapa. 

Family  Turdid<E  —  thrushes,  bluebirds,  etc.  The  thrushes  are  typical 
"  soft-billed  "  birds,  their  food  being  largely  insects,  worms,  spiders,  etc. 
They  also  feed  upon  fruits  in  season,  and  this  has  complicated  the  prob- 
lem of  their  economic  value  up  to  within  recent  years.  A  closer  analy- 
sis of  their  foods  has  demonstrated  that  the  birds  prefer  native  wild 
fruits  to  cultivated ;  hence  this  problem  may  be  solved  humanely  and 
scientifically  by  planting  a  succession  of  these,  ^sthetically  the  thrushes 
are  among  our  most  highly  valued  songsters,  and  structurally  they  rank 
as  the  highest  family  of  birds. 

Wood  thrush  —  Hylocichla  mustelina. 
Wilson's  thrush  —  Hylocichla  fuscescens. 
Hermit  thrush  —  Hylocichla  guttata  pdllasi. 
American  robin  —  Planesticus  migratorius. 
Bluebird  —  Sidlia  sialis. 


Fig.  25.  Cariyiiig  incubated  eggs  (ruffed  grouse)  and  the  result 
Photograph  by  the  author 


52 


METHODS  OF  BIED  STUDY 


53 


It  should  be  repeated  that  the  above  hst  is  suggested  for 
central  New  England,  and  that  it  should  be  freely  modified  to 
fit  the  species  and  problems  of  other  sections. 

One  of  the  most  interesting  civic  problems  in  this  field  re- 
lates to  conservation  of  American  game  bu-ds.  To  accomplish 
this  we  need  three  things :  (1)  national  control  of  migratory 
species;  (2)  universal  property  right  in  all  game  reared  by 
individuals;  (3)  study  of  methods  of  breeding  and  rearing 
under  control  all  kinds  of  American  game  birds. 

The  third  factor  will  speedily  follow  from  legal  authoriza- 
tion of  game  breeding,  (2),  which  is  being  accorded  by  re 
cent  state  laws.  J£ollow  legislation  ^  your  own  state  and 
work  for  this  at  every  opportunity,'  As  long  as  the  State 
claims  ownership  in  all  game,  people  cannot  afford  to  raise  it, 
and  often  the  lawless  trespassing  and  annoyance  of  hunters 
on  private  land  make  the  owners  wish  that  the  game  were 
exterminated.  As  soon  as  we  can  secure  the  proper  freedom 
from  laws  which  work  against  conservation,  breeding  of  game 
birds  will  become  one  of  the  most  profitable  of  occupations. 

Thousands  of  nests  of  wild  ducks,  geese,  bobwhites,  wild 
turkeys,  ruffed  grouse,  and  prairie  chickens,  are  yearly  broken 
up  by  various  farmmg  or  logging  operations.  The  eggs  at  an}" 
stage  of  incubation  may  be  saved  by  carrying  in  the  hat,  as 
shown  in  Fig.  25.  If  all  these  eggs  could  be  saved,  they  w^ould 
speedily  yield  birds  enough  to  restock  portions  of  the  country 
from  which  the  species  have  been  exterminated. 


.\ 


Fig.  26.  Black  Hills  National  Forest 
United  States  Bureau  of  Forestry 

64 


CHAPTER  VI 

TREE   STUDY  AND  CIVIC   FORESTRY 

Why  are  there  trees  I  never  walk  under  but  large  and  melodious  thoughts 
descend  upon  me  ?  —  Walt  Whitman 

How  foolish  does  man  appear  to  be  in  destroying  the  mountain  forests, 
for  thereby  he  deprives  himself  of  wood  and  water  at  the  same  time. — 
Alexander  von  Humboldt 

It  is  undoubtedly  true  that  more  pine  timber  has  been  destroyed  by  fire 
than  the  lumbermen  have  ever  cut.  —  Green 

The  problem.  The  annual  growth  of  all  the  forests  of  the 
United  States  is  7,000,000,000  cubic  feet  of  wood,  while  our 
yearly  consumption  amounts  to  more  than  20,000,000,000 
cubic  feet.  In  addition  to  this,  since  1870  forest  fires,  for  the 
most  part  preventable,  have  caused  a  yearly  loss  of  fifty  lives, 
150,000,000 worth  of  lumber,  and  a  destruction,  even  greater, 
of  all  young  growth  and  of  soil  fertility  by  the  burning  of  the 
vegetable  mold  of  the  forest  floor.  Floods  in  the  lower  Missis- 
sippi alone  during  1912,  due  to  unwise  and  uncivic  deforesta- 
tion, in  the  main,  caused  great  loss  of  life,  extreme  privation, 
and  damage  estimated  at  $82,187,670.  While  this  torrential 
run-off  is  flooding  the  lower  river  valleys,  millions  of  woodland 
springs  and  even  wells  back  in  the  foothills  and  mountains 
are  going  dry.  From  one  to  two  thousand  million  tons  of  the 
finest  and  richest  soil  —  enough  to  bury  Rhode  Island  from 
one  to  two  feet  deep  —  is  being  washed  yearly  from  the  farms, 
where  it  may  be  worth  a  dollar  a  ton,  into  our  harbors,  where 
it  costs  millions  to  dredge  it  out  of  the  way. 

Increasing  population  and  consumption  of  wood,  decreasing 
forests,  inadequate  control  of  forest  fires,  increased  washing 

65 


5(i  (IVIO  BIOLOGY 

of  soil,  floods  rising  higher  each  year  ^  these  are  the  main 
elements  in  the  problem.  Records  of  flood  plane  of  the  Missis- 
sippi at  New  Orleans  are  as  follows : 

Date  Feet 

1882  . 15.8 

1892 17.6 

1903 ,  20.3 

1912 22.0 


Fk;.  27.   Flood  showing  result  of  (leforestHliuii 

If  the  flood  of  1912  had  not  broken  the  levees  and  poured 
over  17,605  square  miles  above  the  city,  the  flood  might  have 
risen  to  thirty  feet  at  New  Orleans. 

Vital  civic  cooperation  must  be  developed  in  growing  more 
wood,  in  holdmg  the  water  and  soil  where  they  belong  and 
can  do  the  most  good  on  every  farm,  and  in  prevention  of 
forest  fires. 

These  are  not  matters  of  private  individual  right  and  con- 
trol; they  are  civic  and  touch  the  life  of  the  whole  people. 


TREE  STUDY  AND  CIVIC  FORESTRY  57 

Every  particle  of  soil  that  a  fanner  in  Pennsylvania,  Minnesota, 
or  Montana  allows  to  wash  from  his  farm  eventually  raises 
the  mud  bed  of  the  Mississippi,  helps  to  cause  floods,  taxes 
the  nation  to  build  higher  levees.  The  clearing  of  a  watershed 
at  the  headwaters  of  the  Ohio  or  Missouri  is  the  business  of 
every  one  whose  spring  or  well  runs  dry  below  it  or  whose 


Fig.  28.  Deforested  slope,  North  Carolina,  showing  erosion 
United  States  Bureau  of  Forestry 

home  is  flooded  farther  down  the  rivers,  and  also  of  every  one 
who  is  taxed  or  who  is  called  upon  to  contribute  or  to  suffer 
in  sympathy  for  the  common  loss. 

Solution  of  problem.  By  the  adequate  planting  of  trees  on 
every  hill  and  mountain  side  and  along  every  gully  and  ravine, 
the  rootlets  of  which  will  bind  the  soil  and  filter  the  water  as 
it  falls,  we  should  have  the  water  leaving  every  farm  clear  as 
crystal  from  perennial   springs.     Vast  national  projects   are 


58  CIVIC  BIOLOGY 

afoot  for  building  dams  and  impounding  the  flood  waters  of 
our  streams  and  rivers.  Much  of  this  will  be  necessary  on 
account  of  past  mistakes  in  clearing  watersheds  and  also  on 
account  of  the  original  configuration  of  certain  regions ;  but  first, 
and  in  connection  with  these  plans,  we  should  unite  as  a  whole 
people  in  planting  trees  to  conserve  both  soil  and  water  on  the 
farms.  Otherwise,  under  present  ignorance  and  mismanage- 
ment, how  long  will  it  be  before  our  reservoirs  are  filled  to  the 
tops  of  their  dams  with  mud  ? 

Observe  and  study  typical  springs  and  streams,  and  learn 
the  history  of  them  for  a  number  of  years.  Have  they  shrunk 
or  gone  dry  ?  If  so,  is  it  because  woods  have  been  cut  above 
their  sources  ?  They  may  be  restored  by  replanting  the  water- 
sheds. Has  it  been  necessary  to  deepen  wells  during  periods 
of  drought  ?  Has  a  man  the  moral  right  to  clear  off  a  woods 
that  will  cause  his  neighbor's  spring  or  well  to  go  dry  ? 

Study  in  a  practical  way  what  the  local  streams  are  carrying, 
if  muddy.  Temporary  streams  will  serve,  if  permanent  ones 
are  not  available.  After  a  freshet,  are  some  streams  clear  and 
others  muddy  ?  How  do  their  relations  to  woodlands  explain 
the  difference  ?  Follow  up  a  muddy  stream  and  find  where 
the  soil  is  being  eroded.  Can  you  sketch  a  plan  of  planting 
with  trees  or  permanent  grass  to  prevent  this  ?  Make  a  list 
and  map  of  all  the  places  in  the  district  that  are  washing 
badly,  or  survey  typical  farms  with  this  feature  in  mind. 
Sketch  a  plan  of  planting  which  will  improve  conditions 
throughout  the  district.  After  this  has  been  perfected  and 
thoroughly  discussed  by  the  class  and  with  parents  most  con- 
cerned, arrange  for  publication  of  the  plan  in  local  papers  or 
make  it  the  subject  of  consideration  in  a  community  meeting. 
All  can  then  arrange  for  saving  or  procuring  the  necessary 
seeds  or  young  trees  and  for  doing  the  actual  planting.  If  not 
too  extensive,  possibly  all  of  this  work  can  be  done  in  outdoor 
laboratory  periods  by  the  class.    At  least  the  seeds  might  be 


TEEE  STUDY  AND  CIVIC  FORESTRY 


59 


gathered  and  many  of  the  young  trees  be  reared  for  a  year 
or  two  in  a  nursery  in  connection  with  the  school  garden.  • 

Suggestions  for  tree  planting.  The  general  plan  should  insure 
having  the  most  valuable  trees  for  each  location  as  the  per- 
manent stand.  It  will  thus  be  necessary  to  study  conditions 
under  which  the  different  species  will  grow  to  best  advantage. 
Some  species  bear  shade  or  sun  better  than  others  when  they 
are  young.  Analyze  and  study  how  and  where  young  trees 
are  thriving  best.  Especially  note  which  species  grow  best  on 
the  driest  hillsides  and  along  the  banks  of  brooks  and  streams. 
It  is  often  necessary,  and  profitable  as  well,  to  plant  quick- 
growing,  sun-enduring  species  as  ''  nurse  trees "  for  a  more 
valuable  permanent  stand. 

The  following  table  suggests  possibilities  in  handling  the 
different  species  of  Eastern  conifers  and  hard  woods  with  refer- 
ence to  tolerance  of  shade  or  sun. 


Shade  Bearers 

\     Intermediates 

Light  Demanders 

Conifers  : 

White  cedar 

Loblolly  pine 

Long-leaf  pine 

Sugar  pine 

Spruces 

Virginia  scrub  pine 

Short-leaf  pine 

Scrub  pine 

Balsam 

White  pine 

Bald  cypress 

Cuban  pine 

Arbor  vitae 

Tamarack 

'Yellow  pine 

Hemlocks 

Jack  pine 

Pitch  pine 

Spruce  pine 

Red  pine 

Red  cedar 

Rock  pine 

Hard  woods  : 

Beech,  Ehn 

Chestnut 

Sourwood 

Cottonwoods 

Black  gum 

Black  walnut 

Locusts 

Red  gum 

Maples,  hard. 

Butternut 

Yellow  poplar 

Hickory 

red,  silver 

Sycamore 

Oaks 

Black  cherry 

Basswood 

Birches 

White  elm 

Ironwood 

Willows 

Mulberry   - 

Note  to  Teacher.    As  early  as 

possible  in  the  year  discuss  with 

the  class  a  list  of  trees  desirable  to  study,  and  apportion,  either  by 
choice  or  lot,  one  or  more  species  to  each  pupil,  according  to  sugges- 
tions for  the  White  Pine,  p.  4 .    Each  will  then  be  responsible  for  seeds, 


60 


CIVIC  BIOLOGY 


Nut  trees.  The  rocky  hillsides  of  Italy  and  Spam,  planted 
to  chestnuts,  are  said  to  produce  without  labor  as  valuable 
crops  as  our  own  best  wheat  lands.  We  are  importing  annu- 
ally over  114,000,000  worth  of  nuts.    How  many,  even  then, 

liave  all  the  nuts  they 
want  ? 

Make  careful  collec- 
tions of  all  the  differ- 
ent nuts  in  the  district 
and  prepare  them  for 
exhibition  in  class,  keep- 
ing records  of  trees  that 
produce  the  best.  Pre- 
serve as  many  as  pos- 
sible of  the  best  for 
planting,  exchange  with 
other  schools,  and  ar- 
range, if  possible,  to  buy 
seeds  or  young  trees,  or 
obtain  scions  from  the 
best  varieties  of  pec^an, 
hickory,  walnut,  and 
chestnut  that  can  be  had 
from  any  part  of  the 
country.  Organize  ex- 
hibits of  nuts  in  connec- 
tion with  local  horticultural  fairs.  By  these  means  we  may 
improve  quality  and  increase  yield  of  nuts  to  any  desu^ed 
amount.  At  the  same  time  the  wood  of  our  native  nut  trees, 
—  hickory,  black  walnut,  chestnut,  —  for  certain  uses,  is  the 
best  we  can  grow. 

flowers,  seedlings,  and  other  specimens  of  his  tree  or  trees,  when  needed 
by  the  class.  Have  each  pupil  study  and  be  prepared  to  describe  the 
method  each  tree  has  developed  for  scattering  and  planting  its  own  seeds. 


Fig.  29.  Young  black-wahuU-  tree 

The  nuts  liati^  on  a  few  days  after  the  leaves 
have  fallen 


TREE  STUDY  AND  CIVIC  FORESTRY 


61 


State  and  national  helps.  The  national  Bureau  of  Forestry 
and  your  state  forester  priiit  a  number  of  practical  bulletins 
and  forestry  leaflets,  which  may  be  obtained  gratis  or  at  cost. 
These  will  give  directions  for  gathering,  storing,  and  planting 
different  tree  seeds,  and  advice  as  to  best  species  to  plant.  Tree 
seeds  and  even  young  seedling  trees  may  be  obtained  from 
state  or  (in  Canada)  from  provincial  departments  of  forestry. 


Fit;.  30.  Crop  uf  tree  shown  in  Fig-.  29 

AVe  do  not  have  to  "  wait"  fifteen  years  for  such  a  crop;  we  just  plant  the  nut 
and  go  about  our  business 

Since  the  planting  of  trees  is  an  important  public  service, 
states  are  beginning  to  pass  laws  exempting  land  so  planted 
from  taxation.  ^lassachusetts  and  New  York  exempt  for 
thirty-five  years  all  lands  on  which  not  fewer  than  twelve 
hundred  trees  are  planted  to  the  acre. 

Forest  fires.  In  a  hot,  dry  wind  a  spark  or  carelessly  dropped 
match  may  start  a  fire  which  one  standing  over  it  cannot  stamp 
out ;  and  it  may  run  down  the  wind  faster  than  wild  horses 


62 


CIVIC  BIOLOGY 


can  gallop.  A  smoldering  camp  fire  may  be  blown  into  flame 
by  the  wind  and  give  us  another  story  like  that  of  the  Hinck- 
ley fire,  which  licked  up  several  towns  and  500  people  in  them, 
left  2000  people  homeless,  and  destroyed  $25,000,000  worth 


Fig.  31.  Forest  fire  in  Washington 
Photograph  by  J.  L.  Bridge 

of  buildings  and  timber.  Let  public  and  private  forest-fire 
service  organize  lookouts  and  fire  wardens  and  volunteers,  at 
great  expense ;  all  these  measures  will  not  be  effective  until 
everybody  is  educated  to  be  intelligent  and  careful  about  the 
little  sparks  that  start  the  big  fires. 


TREE  STUDY  AND  CIVIC  FORESTRY 


63 


One  evening  last  September  when  the  men  had  quit  work  and  were  all 
in  camp  or  on  the  way,  a  patrolman  blew  the  fire  signal  at  a  "  donkey  " 
about  sixty  rods  from  camp  and  within  three  minutes  fifty  men  were  at 
work.  In  half  an  hour  there  were  a  hundred,  and  in  fifteen  minutes 
more,  a  hundred  and  fifty.  Even  with  this  prompt  action  it  took  all 
night  and  all  the  next  day  to  extinguish  the  fire.  Now  what  I  should 
like  to  know  is  how  to  keep 
a  fire  from  working  you 
forty  hours  even  when  you 
see  it  start  and  can  get  your 
crew  on  the  ground  at  once. 
It  was  a  dry  slashing  and  a 
cigarette.  How  stop  the 
cigarette  ?  —  Proceedings 
of  Forest-Fire  Conference, 
Seattle,  1912,  p.  19 

This  Ls  the  crucial, 
vital  poiiit  in  civic  co- 
operation, to  have  every 
one,  young  or  old,  na- 
tive or  foreign-born, 
rich  or  poor,  thoroughly 
careful  about  these  lit- 
tle sparks  that  start  the 
big  fires. 

For  outdoor  labora- 
tory work  organize  the 
class  so  as  to  utilize  all 
local  brush  burnings 
and  actual  forest  fires.  Make  practical  demonstrations  of  put- 
ting out  camp  fires  by  the  use  of  water  and  earth.  Teach  the 
factors  that  go  to  make  up  a  safe,  model  camp  fire  —  proximity 
to  water  or  moist  earth,  use  of  stones  and  rocks  to  prevent 
spreading,  and  distance  from  dry  stumps,  logs,  peat,  or  leaf 
mold.  Finally  organize  a  survey  for  danger  spots  and  try 
to  have  these  attended  to  before  the  danger  season. 


Fig.  32.  Forest-fire  lookout,  Croydon  Moun- 
tain, New  Hampshire 
Photograph  by  Charles  I.  Rice 


64 


CIVIC  BIOLOGY 


Causes.  Natural  causes,  lightning  and  friction,  account  for 
few  forest  fires,  and  as  these  occur  during  rainstorms,  there  is 
almost  no  damage  from  them.  Study  local  forest  fires  and 
tabulate  under  the  following  causes: 

Forest  Fihks  ix  Massachusetts  in  1008 


Causk 

NUMBEK 

Remarks 

Railroad  trains  (Locomotives) 

490  (38%) 

Usually  cause  about  50%  of  all 
forest  fires.  Can  be  stopped  by 
proper  use  of  spark  arresters, 
or  by  burning  oil,  by  turning 
hose  into  ashes  before  dump- 
ing, and  by  clearing  roadbed 
of  inflammable  rubbish. 

Sawmills 

12(1%) 

Should  have  men  organized,  and 
be  provided  with  adequate  fire- 

Burning  brusli DO  (7%) 


Smokers Ill  (8%) 


Campers'  fires 1  (0.1%) 

Boys  (incendiary)   .     .     .     .  i  1.50  (11%) 
Unknown I  314  (25%) 


fighting  apparatus. 

Escape  of  these  fires  can  be 
avoided  by  burning  when  snow 
is  on  the  ground  or  during  a 
wet  spell. 

Those  who  must  smoke  in  tlie 
woods  in  a  dry  time  should  be 
compelled  by  law  to  dive  under 
water  to  light  up  and  stay  down 
as  long  as  there  is  a  spark  in 
their  pipes  or  cigarettes. 

Boy  Scouts  may  stop  such  fires. 
Probably  mostly  set  by  smokers 
and  careless  or  incendiary  boys. 


In  all,  for  ^Massachusetts  1378  forest  hres  were  reported 
in  1908,  which  burned  over  40,327  acres  of  woodland,  nearly 
2  per  cent  of  the  wooded  area  of  the  state.  In  the  whole  of 
Prussia  1400  acres  have  been  burned  in  the  past  twenty-five 
years,  or  less  than  0.02  of  1  per  cent  a  year.    At  this  rate  the 


TREE  STUDY  AND  CIVIC  EOKESTRY 


65 


whole  forest  area  in  Massachusetts  would  be  burned  over  in 
about  fifty  years,  and  in  Prussia  in  5000  years.  Why  this 
difference  ? 

The  actual  loss  by  forest  fires,  although  great,  is  not  the 
worst  feature  of  the  situation.    Forest  fires  discourage  tree 


''V  U'SIH 

■aiiiPv^fli^:   ,       ! 

^^^^9 
'"^'.^^^^H 

-*      ^  ^1^ 

Fig.  83.  Safe  burning  of  brush 
United  States  Bureau  of  Forestry 

planting  everywhere.   Reduce  or  banish  entirely  danger  of  fires 
and  tree  planting  will  become  a  safe  and  profitable  investment. 

XoTE  TO  Teacher.  After  working  over  the  ground  and  with  special 
reference  to  local  problems  ask  the  town  fire  warden  to  visit  the  class 
and  explain  the  state  laws  and  the  apparatus,  equipment,  methods,  and 
organization  of  the  state  and  town  for  preventing  forest  fires  and  for 
quick  work  with  those  that  are  started. 


66 


CIVIC  BIOLOGY 


To  sum  up  the  whole  matter  have  each  member  of  the  class  write  a 
brief  outline  of -a  plan  by  which  he  thinks  forest  fires  can  be  effectively 
prevented  in  the  district,  town,  or  county.  The  best  of  these  plans  may 
be  printed  in  local  papers  or  used  as  the  basis  for  discussion  in  a  timely 
neighborhood  meeting.  With  every  township  safe  and  protected  by  a 
well-organized  community,  the  entire  country  will  be  equally  safe. 

Forest-fire  laws.  Secure  the  latest  forest-fire  laws  in  your 
state  or  province  and  familiarize  yourself  with  them.  These 
laws  represent  the  best  thought  of  your  community  on  the 
subject.    What  can  you  do  to  help  in  making  the'm  effective  ? 


CHAPTER  VII 

PLANT  PROBLEMS:   PRESERVATION  OF  WILD  FLOWERS, 
CONTROL  OF  WEEDS,  MEDICINAL  AND  POISONOUS  PLANTS 

Groups  of  plants  present  civic  problems  of  no  less  impor- 
tance than  those  of  birds  and  insects.  For  beautiful  landscapes 
the  people  of  a  locality  must  learn  to  cooperate  in  preserving 
and  planting  native  trees,  shrubs,  and  vines.  Additional  study 
of  these  is  taken  up  from  this  point  of  view  in  chapters  on 
Forestry  and  Landscape  Gardening. 

Conservation  of  native  plants.  Many  of  our  most  beautiful 
native  plants  are  in  danger  of  extermination.  To  educate 
against  wanton  destruction  a  society  of  national  membership 
has  been  organized,^  and  if  all  can  be  induced  to  join  in  rea- 
sonable conservation  of  these  common  interests,  we  may  have 
much  more  attractive  and  interesting  woods,  parks,  and 
country  roadsides.  Do  you  have  trailing  arbutus,  fringed  gen- 
tian, cardinal  flower,  maidenhair  fern,  pink  lady's-slipper  grow- 
ing in  abundance  ?  By  inquiry  from  parents,  grandparents,  or 
older  members  of  the  community,  can  jo\i  make  out  a  list  of 
native  plants  that  have  become  rare  and  need  protection  in 

1  Society  for  the  Protection  of  Native  Plants,  Boston,  Massachusetts. 
For  leaflets,  address  the  Boston  Society  of  Natural  History. 
This  society  urges  that  we  all  use  : 

1.  Moderation.  Do  not  pick  all  that  you  find.  Many  flowers  must  be  left  to 
develop  seeds  for  future  plants. 

2.  Care.  Never  pull  up  the  plant,  for  the  roots  are  of  no  use  in  a  bunch  of 
flowers,  and  their  destruction  means  the  extinction  of  the  plant.   Cut  when  possible. 

3.  Judgment.  Many  flowers,  such  as  wild  roses,  asters,  and  goldenrod,  may 
be  picked  with  impunity,  but  when  flowers  are  few  or  rare  do  not  pick  them.  Do 
not  pick  flowers  which  must  die  before  you  reach  home,  nor  great  quantities  of 
those  flowers  whose  grace  and  beauty  are  better  seen  in  a  few  than  in  many 
massed  together. 

67 


68  CIVIC  BIOLOGY 

the  locality  ?  Discuss  together  as  a  class  plans  for  bringing 
them  back  to  their  native  haunts. 

Weeds.  Fighting  weeds  is  often  the  most  laborious  and  ex- 
pensive part  of  gardenuig  and  of  raising  certain  staple  crops. 
It  was  formerly  said  that  weeds  were  the  gardener's  friends, 
because  they  made  necessary  the  frequent  stirring  of  the  soil, 
which  was  considered  beneficial  to  plant  growth.  Recent  ex- 
periments in  raising  corn  have  shown  equal  production  with 
absolutely  none  of  this  laborious  stirring  of  the  soil.  In  fact, 
earlier  experiments  on  the  root  system  of  the  corn  plant  had 
proved  that  the  farmer  actually,  and  very  materially,  reduced 
his  corn  crop  by  deep  cultivation.  Other  crops  await  similar 
investigation.  The  results  so  far  have  been  to  rate  the  damage 
caused  by  these  "  robber  plants  "  at  much  liigher  figures  than 
formerly.  If  we  could  prepare  the  ground  and  plant  our  gardens 
and  fields  and  never  see  a  weed,  the  labor  and  cost  of  produc- 
tion from  the  soil  might  be  reduced  nearly,  or  quite,  one  half. 

Damage  caused  by  weeds.  Weeds  are  defined  as  ''plants 
which  persist  in  growing  where  they  are  not  wanted."  No 
less  than  seven  hundred  such  plants  are  listed  for  tlie  entire 
United  States.  Make  a  list  of  weeds  that  are  locally  most 
noxious.  Weeds  reduce  yield  of  crops  by  crowding,  and  by 
robbing  the  plants  of  water  and  food  in  the  soil  and  of  light 
in  the  air.  They  injure  seeds  and  flour,  cause  objectionable 
flavors  in  milk,  and  poison  stock.  A  recent  estimate  by  the 
Division  of  Farm  ^lanagement  of  the  United  States  Depart- 
ment of  Agriculture  places  the  total  annual  damage  of  weeds 
at  $500,000,000.  What  part  of  this  yearly  tax  is  imposed  on 
your  own  home,  garden,  or  farm  ?  What  is  the  annual  damage 
and  cost  of  fighting  weeds  in  your  district,  township,  county, 
or  state  ?  ^  Can  you  propose  a  plan  of  cooperative  work  by 
which  this  may  be  reduced  ? 

1  Secure  your  state  bulletins  on  weeds  to  assist  in  working  out  the  prob- 
lems suggested.    Write  also  for  the  Weed  Laws  of  your  state. 


PLANT  PROBLEMS  69 

Control  of  weeds.  Select  the  largest  specimens  to  be  found 
in  roadsides  and  vacant  lots,  barnyards,  and  gardens,  of  per- 
haps ten  of  the  worst  local  weeds;  dry  carefully,  thresh  out 
and  count  or  estimate  the  number  of  seeds  in  each.  No  one 
who  takes  part  in  such  a  lesson  can  ever  be  indifferent  to  al- 
lowing such  weeds  to  ripen  their  thousands  or  even  millions 
of  seeds,  1  when  a  stroke  of  scythe  or  hoe  at  the  right  time 
would  stop  them. 

Failure  to  study  weeds  and  get  clear  ideas  of  their  powers 
of  reproduction  and  of  effective  methods  of  exterminating 
them  is  responsible  for  the  fact  that  more  decisive  headway 
has  not  been  made  in  their  control.  Further  topics  in  this 
connection  are  the  following: 

Dispersal  of  weed  seeds.  Along  with  rats,  English  sparrows, 
the  San  Jose  scale,  and  gypsy  moth,  many  of  our  worst  weeds 
are  immigrants  from  the  Old  World.  They  come  mixed  with 
seeds^and  grains,  in  merchandise,  and  in  all  kinds  of  packing 
materials.  Watching  ports  of  entry  has  not  succeeded  in  keep- 
ing out  these  unwelcome  guests.  Our  only  hope  lies  in  knowl- 
edge sufficient  to  recognize  and  give  the  alarm  and  unite  in 
eradicating  vicious  importations  before  they  become  widely 
established. 

The  more  widely  a  plant  is  able  to  scatter  its  seeds,  the 
bel;fcer  the  chance  of  growth.  Naturally  weeds  lead  the  world 
of  plants  in  effective  devices  for  dispersing  their  seeds.  They 
are  aided  by  different  elements  in  the  environment  —  winds, 
flowing  waters,  and  animals.    Make  a  collection  of  weed  seeds 

1  This  suggestion  carried  out  in  the  Cleveland  Normal  School  yielded  the 
following  results : 

Milkweed — Asclepias  syrlacea 2,510  seeds 

Sticktights  —  Bidens  frondosa 7,040  seeds 

Pigweed — Amaranthus  hyhridus ;305,760  seeds 

Purslane  — Por^w/aca  oteracea       1,250,000  seeds 

Lamb's-quarters — Chenop odium  album     .     .     .     .  1,613,320  seeds 
Worraseed  —  Chenopodium  anthelmivticunt   .     .      26,085,150  seeds 


70  CIVIC  BIOLOGY 

and  study  with  reference  to  means  of  dispersal.  These  collec- 
tions will  also  be  useful  in  identifying  impurities  in  garden 
and  field  seeds. 

Vitality  of  weed  seeds.  The  great  length  of  time  weed 
seeds  remain  alive  in  the  soil  furnishes  another  strong  reason 
for  not  permitting  them  to  ripen.  Dr.  Beal  has  found  that 
seeds  of  pigweed,  black  mustard,  shepherd's-purse,  pepper- 
grass,  mayweed,  evening  primrose,  smartweed,  purslane,  curled 
dock,  foxtail,  and  duckweed  are  able  to  germinate  after  being 
buried  for  twenty-five  years.  How  much  longer  they  may 
survive  remains  to  be  determined. 

Adaptability.  Weeds,  like  other  plants,  attain  their  best 
growth  under  favorable  conditions  of  soil,  but  they  are  able  to 
produce  seed  under  conditions  of  greatest  hardship.  A  search 
of  clay  banks,  ash  heaps,  gravel  or  cinder  walks  will  reveal 
minute  dwarf  specimens  of  common  weeds.  Weeds  also  show 
extreme  tenacity  of  life  in  many  other  ways.  Uproot  them, 
and  if  a  rootlet  remains  in  the  soil,  it  will  continue  to  grow 
and  mature  seed  as  it  lies  on  the  ground.  If  trampled  down, 
branches  that  retain  a  shred  of  connection  with  the  stem  re- 
main fresh  and  produce  seed.  Even  when  cut  close  to  the 
ground,  new  branches  quickly  appear.  An  outdoor  lesson 
devoted  to  this  topic  will  prove  valuable  in  many  connections. 

Classes  of  weeds.  Success  in  fighting  weeds  must  depend 
upon  knowledge  of  each  species.  The  methods  used  will  de- 
pend in  a  general  way  upon  whether  the  particular  weed  is : 

An  annual.  Most  garden  weeds  —  chickweed,  purslane, 
lamb's-quarters,  pigweed,  ragweed,  pigeon  grass  —  complete 
their  life  cycle  in  a  single  season.  To  completely  eradicate 
these  from  the  soil  it  is  only  necessary  to  prevent  any  from 
maturmg  seed  until  seeds  already  in  the  ground  have  germi- 
nated. Barnyard  manure  or  loam  may  reseed  a  clean  garden 
plot,  if  not  applied  with  great  care.  If  manure  is  spread  upon 
the  top  after  plowing,  all  weed  seeds  in  it  are  more  likely  to 


PLANT  PROBLEMS  71 

germinate  the  first  year  than  if  they  are  plowed  under  deeply. 
Some  weeds  of  this  class  —  chickweed,  peppergrass,  shepherd's- 
purse  —  germinate  late  in  the  summer  or  fall,  live  through 
the  winter,  and  are  known  as  "  winter  annuals  "  in  latitudes 
where  this  occurs. 

A  biennial.  These  plants  complete  their  life  cycle  in  two 
years  and  hence  rapidly  disappear  if  prevented  from  maturing 
seed.  Burdock,  bull  thistle,  mullein,  teasel,  and  wild  carrot, 
all  immigrants  from  the  Old  World,  are  familiar  examples. 

A  perennial.  Couch  grass  (a  native  American),  Canada 
thistle,  curled  dock,  plantain,  wild  onion,  milkweed,  bind- 
weed, most  of  them  importations  from  the  Old  World,  are 
examples.  Most  of  the  hard  problems  relate  to  weeds  of  this 
class.  The  plants,  besides  producing  seeds,  live  from  year  to 
year  m  the  ground  by  means  of  perennial  crowns,  tubers,  and 
burrowing  rootstocks.  Cultivation  which  would  eradicate  an- 
nuals or  biennials  may  serve  merely  to  subdivide  and  increase 
these  pests  of  the  soil. 

The  fact  that  certain  weeds  tend  to  thrive  best  with  certain 
crops  suggests  rotation  as  a  means  of  control.  Land  should 
have  a  radical  change  of  treatment,  if  badly  infested  with 
weeds.  Annual  weeds  of  gardens  and  cultivated  fields  die 
out  if  the  land  is  seeded  to  grass.  This  applies  to  grainfields 
which  have  become  seeded  to  chess,  cockle,  or  ragweed.  Pas- 
ture lands  "  run  out "  to  perennial  weeds  should  be  planted 
to  annual  crops.  Thus  a  system  of  field  rotation  and  general 
management  may  be  adopted  which  shall  give  weeds  the  least 
possible  chance  to  survive. 

Chemical  weed  killers^  herbicides.  Salt  or  strong  brine,  arse- 
nate of  soda,  coal  oil,  crude  sulphuric  acid,  carbolic  acid,  and 
sulphates  of  copper  or  iron  are  the  chemicals  usually  employed 
and  suggest  interesting  experiments  for  the  lawn  or  garden. 

Medicinal  plants.  Many  crude  drugs  and  aromatic  herbs 
used  as  condiments  are  now  imported,  although  they  grow  in 


72 


CIVIC  BIOLOGY 


the  United  States.  The  table  ^  below  gives  the  amounts  brought 
in  and  the  prices  we  pay  for  some  of  our  most  common  weeds. 


Weeds 


Docks — Kamea;  species    .    .    . 
Burdock  —  Arctiian  lappa  Jj.  . 

Dandelion  —  Tarajraciun  tarax- 
acum   

Quack  or  couch  ,<i;rass  —  Agro- 
pyron  repenft  L 

Mullein  —  VerhaHCum  thapsus  L. 

Tansy —  Tanacetum  vulgare  L. 

Horehound  —  Marnihium  vul- 
gare L.  .    .  * .    .    .  '.    .    .    . 

Jimson  weed  —  Datura  stramo- 
nium L 

Poison  hemlock  —  Couium  mac- 
ulatum  L 

Black  and  white  mustard  —  Si- 
napis  species 


Parts  used 

Amount  im- 
FOKTED  IX  Poinds 

PUICE   I'AU) 

IN  Cents 
PER  Pound 

Ro(>ts 

125,000 

2-8 

Roots 

50.000 

.3-8 

Seeds 

5-10 

Hoots 

115,522 

4-0 

Kootstock 

250,000 

3-7 

Leaves 

5.000 

2^-5 

Flowers 

25-75 

Leaves  and 

tops 

.30,000 

3-0 

Leaves  and 

tops 

125,000 

.3-8 

Leaves 

100,000-150,000 

21-8 

Seeds 

10,000 

3-7 

Seeds 

20,000 

3 

•  Leaves 

10,000-20,000 

4 

Seeds 

5,302,876 

3-0 

While  the  demand  for  medicinal  Aveeds  is  not  great,  market- 
ing those  that  have  useful  properties  would  tend  to  check  their 
spread,  and  might,  in  turn,  pay  at  least  for  their  removal. 

Other  native  drug  plants.  Clearing  of  the  forests  and  the 
work  of  the  drug  collector  have  resulted  in  almost  extermi- 
nating many  of  our  native  drug  plants.  To  save  these  the 
Bureau  of  Plant  Industry  has  undertaken  the  work  of  domes- 
ticating them  with  the  hope  not  only  of  supplying  the  home 
market  but  also  of  exporting  them. 

In  the  gardens  at  Washington  some  success  in  an  experi- 
mental way  has  been  attained  in  raising  goldenseal,  cascara 

1  Compiled  from  Bulletin  No.  188,  United  States  Department  of  Agricul- 
ture, "Weeds  used  in  Medicine."  This  gives  prices  and  methods  of  pre- 
paring for  market. 


PLANT  PROBLEMS  73 

sagrada,  Seneca  siiakeroot,  and  purple  cornflower.  Ginseng 
has  already  been  domesticated,  the  total  yield  hi  states  east  of 
the  Mississippi  River  being  about  one  million  dollars  annually. 

A  considerable  portion  of  crude  drugs  used  in  the  United 
States  is  of  foreign  origin.  To  supply  the  home  market  and 
save  millions  of  dollars  now  spent  on  foreign  drugs,  the 
Bureau  has  interested  itself  in  the  experimental  culture  of 
these  foreign  plants  in  soil  and  climate  similar  to  their  own. 
Plots  of  Asiatic  poppy,  camphor  trees,  cinchona,  belladonna, 
foxglove,  and  red  peppers  have  been  planted  in  suitable  parts 
of  our  country. 

Poisonous  plants.  Certain  plants  are  poisonous  either  when 
handled  or  eaten.  For  lack  of  statistics,  no  estimate  can  be 
given  as  to  the  amount  of  damage  done  by  them. 

Complaints  have  been  so  numerous  against  various  plants 
which  poison  man  and  animals,  that  the  Government  has 
investigated  them  and  has  issued  a  number  of  bulletins  on 
poisonous  plants  of  the  United  States.^  (See  Bulhthi  86^ 
"  Thirty  Poisonous  Plants.") 

Of  the  thirty  plants  described,  about  one  third  are  weeds ; 
the  others  are  fungi,  lierbs,  shrubs,  and  trees.  The  most 
poisonous  plants  are  mushrooms  (Amanita  mi(scaria  and  Ama- 
nita phalloides)^  the  various  species  of  water  hemlock  (^Oieiita^, 
and  the  loco  weed  (Astragalus).  Damage  to  the  live-stock 
business  from  loco  weed  is  enormous.  Colorado,  in  a  vain 
attempt  to  exterminate  it,  spent  $200,000  in  bounties  between 
the  years  1881  and  1895. 

1  Bulletins  from  United  States  Bepartment  of  Agriculture  : 

28.  W^eeds  and  how  to  Kill  them. 

86.  Thirty  Poisonous  Plants. 
188.  Weeds  used  in  Medicine. 
279.  Methods  of  eradicating  Johnson  Grass. 

Besides  these,  almost  every  state  issues  complete  and  fully  illustrated  bul- 
letins on  its  own  weeds.    Canada  issues  weed  bulletins  on  an  elaborate  scale. 


74 


CIVIC  BIOLOGY 


Much  suffering  is  caused  by  poison  ivy,  the  active  poison 
being  a  nonvolatile  oil  found  in  all  parts  of  the  plant  —  even 
the  dried  wood.  The  oil  is  soluble  in  alcohol  and  may  be 
removed  from  the  skin  by  thoroughly  bathing  exposed  parts 
in  alcohol  and  then  washing  off  with  water.    An  alcoholic 


Fig.  34.  Purple  or  woolly  loco  weed  —  Astragalus  moUissimus 

Photograph  by  C.  Dwight  Marsh,  United  States  Department  of  Agriculture, 

Bulletin  112 

solution  of  sugar  of  lead  (lead  acetate)  destroys  the  oil.    The 
same  remedy  applies  to  poison  sumac  and  poison  oak. 


Additional  Studies 

1.  Prepare  a  list  of  common  weeds  found  along  the  roadside,  rail- 
roads, in  grass,  field,  backyard,  and  garden. 

2.  Compare  number  of  seeds  borne  by  a  weed  with  those  of  a  wheat, 
oat,  or  barley  plant. 

3.  What  weeds  do  you  know  that  are  eaten  as  vegetables  ? 

4.  How  is  the  fact  that  weeds  are  not  valuable  food  for  domestic 
animals  to  their  advantage  ? 


PLANT  PROBLEMS  75 

5.  Discuss  the  advisability  of  having  foreign  seeds  and  grains  in- 
spected before  being  allowed  to  enter  this  country. 

6.  Discuss  the  advantage  of  smothering  weeds  with  quick-growing, 
thickly  seeded  crops,  like  red  clover  an^  rye. 

7.  Test  the  germinating  power  of  a  weed  by  placing  its  seeds  on  damp 
blotting  paper  between  two  plates. 

8.  Record  instances  observed  of  weeds  damaging  food  plants.  What 
did  Darwin  mean  by  the  "  struggle  for  existence  "  and  "  survival  of  the 
fittest "  ?    (Ref . :  Hodge,  "  Nature  Study  and  Life,"  chap,  vii.) 

Copy  the  following  list  of  poisonous  plants  into  your  notebook,  and 
make  the  acquaintance  of  each  one,  if  possible,  during  outdoor  tramps. 
Increase  the  list  by  wider  observation. 

Poison  ivy  —  Rhus  radicans  [poison  oak,  three-leaved  ivy,  mercury, 
black  mercury,  markweed,  pikry  (Maine)]. 

Poison  sumac  —  Rhus  vernix  [swamp  sumac,  dogwood  (Massachu- 
setts), poison  elder  (Alabama),  poison  ash  (Vermont),  thunderwood 
(Georgia,  Virginia)]. 

Poison  oak  —  Rhus  diversiloba  [poison  ivy,  yeara,  California  poison 
sumac]. 

Poison  hemlock  —  Conium  maculatum  [hemlock,  wild  hemlock,  spotted 
parsley,  stinkweed,  poison  root,  poison  snakeweed,  cashes,  wode-whistle]. 

Water  hemlock  —  Cicuta  maculata  [spotted  parsley,  snakeweed,  beaver 
poison,  musquash  root,  muskrat  weed,  cowbane,  spotted  cowbane,  chil- 
dren's-bane,  death-of-man]. 

Pokeweed  —  Phytolacca  decandra. 

Corn  cockle  —  Agrostemma  githago. 

Black  cherry  —  Prunus  serotina  [wild  cherry,  rum  cherry]. 

Red  buckeye  and  common  horse-chestnut  —  A^sculus  pavia  and 
hippocastanum. 

Broad-leaf  laurel  —  Kalmia  latifoUa  [laurel  (north  of  Maryland),  ivy 
(south  of  Maryland),  mountain  laurel,  sheep  laurel,  poison  laurel,  wood 
laurel,  small  laurel,  high  laurel,  American  laurel,  poison  ivy,  ivy  bush, 
ivy  wood,  big  ivy,  calico  bush,  spoonwood,  kalmia,  wicky]. 

Narrow-leaf  laurel  —  Kalmia  angustifolia  [sheep  laurel,  lambkill,  sheep 
poison,  lamb  laurel,  small  laurel,  low  laurel,  dwarf  laurel,  wicky]. 

Jimson  weed  —  Datura  stramonium  and  D.  tatula,  the  taller  and 
purple-flowered  species  [Jamestown  weed,  common  stramonium,  thorn 
apple,  apple  of  Peru,  devil's  apple,  stinkwort,  stinkweed,  Jamestown  lily, 
white  man's  plant  (by  the  Indians)]. 


76      .  CIVIC  BIOLOGY 

Caper  spurge  —  Eupliorhia  lathyris  [garden  spurge,  mole  plaut,  gopher 
plant,  wolf's-milk,  springwort]. 

Snow-on-tlie-mountain  —  Euphorbia  ihuryinata. 

Other  poisonous  plants  are  : 

Death-cup  mushrooms,  of  the  genus  Amanita. 

American  false  hellebore  —  Veratrum  viride  [white  hellebore,  swamp 
hellebore,  Indian  poke,  pokeroot,  Indian  uncus,  crow  poison,  devil's-bite, 
duck-re tter,  itchweed,  bugbane,  wolfsbane,  bear  corn]. 

Dwarf  larkspur  —  Delphinium  tricorne  [staggerweed  (Ohio)  un<l  ]tur])le 
larkspur — D.  menziesii  (also  D.  hicolor  and  D.  troll  if olium)']. 

Woolly  loco  weed  —  Astragalus  mollissituus ;  and  stemless  loco  weed  — 
Aragallus  Lamhertii  and  A.  lagopos. 

Rattlebox  —  Crotalaria  sagittalis. 

Oregon  water  hemlock —  Cicuta  vagans  (also  C.  orridenialis).   - 

Great  laurel  —  Rhododendron  maxinnim. 

Staggerbush  —  Pieris  mariana. 

Branch  ivy  —  Leucothoe  cateshcei.  , 

Black  nightshade  —  Solan  urn  nigrum. 

Bittersweet — Solanuni  dulcamara. 

Sneeze  weed  —  Helenium  autumnale. 

Zygadenus  venenosus. 

Lupinus  .sericeus. 

Asclepias  speciosa. 

Hyoscyamus  niger. 


CHAPTER  VIII 

HOME   PLANTING  AND   LANDSCAPE  GAPvDENlNG 

A  good  city  can  no  more  successfully  be  imposed  from  without,  than  a 
good  character  can  be  imposed  upon  an  individual.  A  beautiful  city  and  a 
beautiful  public  life  must  be  the  manifestation  of  the  right  spirit  within. 
Therefore  it  is  primarily  incumbent  upon  every  one  interested  in  what  has 
so  happily  been  called  ''the  forward  movement"  to  develop  a  character 
(wholesome),  a  love  for  truth  and  righteousness,  a  (Jhristian  grace.  As  we 
grow  in  knowledge  and  grace,  we  will  reflect  it  in  our  public  life  ;  and  recip- 
rocally, as  our  public  life  advances,  it  will  be  reflected  in  higher  personal 
standards. 

A  Carnegie  may  build  a  library,  a  Marshall  Field  construct  a  great 
nuiseum,  a  Rockefeller  found  a  great  university,  but  oilr  cities  must  be  built 
•by  the  people  themselves.  There  is  no  magic  to  be  availed  of ;  no  Pauline 
conversion  to  be  expected.  Our  municipal  salvation  must  be  wrought  out 
patiently,  carefully,  ofttimes  in  fear  and  trembling,  and  not  by  any  one  or 
two,  but  by  the  whole  community.  —  C.  R.  Woodruff 

Just  as  the  State  grew  out  of  the  family,  so  the  beautiful  city  can  only  be 
the  outcome  of  the  beautiful  home.  —  Alexandra  Blumberg 

111  general  the  physical  features  of  a  landscape  supply  the 
skeleton  which  life  clothes  with  beauty  of  form  and  color,  and, 
like  skeletons,  lifeless  deserts  or  mountains  are  gloomy  and 
forbidding.  Without  plants  the  animation  imparted  by  animal 
life  is  also  lacking,  and  the  silence  and  loneliness  of  such  scenes 
become  oppressive.  Hence  the  living  factors  which  add  attrac- 
tiveness and  charm  to  home  and  country  are  legitimate  topics 
for  study. 

"  Beautiful  America  "  is  the  watchword  of  a  national  move- 
ment represented  in  organized  form  by  the  American  Civic 
Association.  This  organization  stands  for  more  beautiful  homes 
and  country  roads,  more  beautiful  towns,  cities,  streets,  and 

77 


78 


HOME  PLANTING  AND  LANDSCAPE  GARDENING     79 


public  parks  and  buildings,  the  abatement  of  smoke  and  billboard 
nuisances,  conservation  of  the  natural  beauties  of  forest,  moun- 
tain, waterfall,  woodland,  spring,  glen,  gorge,  and  canyon  —  for 
these  real  values  to  the  whole  people  of  a  beautiful  America. 

The  appearance  of  a  country,  especially  of  its  homes,  affords 
the  best  index  of  the  char- 
acter of  a  people.  Some 
homes  express  taste,  re- 
finement, good  sense,  and 
morals  which  warm  the 
heart  of  the  passer-by  with 
a  friendly  feeling  for  those 
who  dwell  within.  Some 
express  pride  and  repel 
with  ostentatious  display 
of  wealth.  Many  are  mere 
muddles,  accidents,  com- 
mercial affairs  of  the  nur- 
seryman. With  the  advent 
of  the  modern  landscape 
gardener  perhaps  the 
greatest  present  danger 
is  the  monotony  of  set 
planting  —  a  bit  of  shrub- 
bery here,  another  there, 
"  just  so,"  which  is  frankly 
more  tiresome  than  nat- 
ural accidents. 

The  practical  biology  of  landscape  gardening  relates  to 
effective  planting  of  the  home  or  street,  park,  town,  or  city.  It 
consists  in  problems  of  forming  pictures  with  actual  trees, 
shrubs  and  vines,  lawns  and  flowers ;  and  the  first  requisite 
for  success  must  be  a  clear  knowledge  of  the  living  things 
with  which  we  build.    We  must  also  bear  in  mind  that  we  are 


Fig.  36.  Lancaster  elm,  after  the  storm 


80  CIVIC  BIOLOGY 

forming  not  only  one  picture  but  a  series  of  pictures  to  be 
viewed  from  different  directions,  and  that  planting  is  most 
effective  which  yields  the  most  pleasing  vistas.    Then  the 


Flu,  37.  Lancaster  elm 
Results  of  neglect  and  vandalism  (the  cavity  had  been  burned  out) 

pictures  will  come  and  go,  from  the  red  maples,  pussy  willows, 
peach  and  apple  blossoms  of  spring,  through  the  procession  of 
summer  bloom,  the  fruits  and  foliage  of  autumn,  to  the  crystal 
fairy  lands  of  ice  storms  and  snow  scenes  of  winter.  Then,  too, 


HOME  PLANTING  AND  LANDSCAPE  GARDENING  81 

our  best  effects  will  lack  aiiiniatioii  and  charm  without  the 
action  and  music  of  birds ;  and  to  complete  the  whole,  we  nuist 
have  fragrance  —  apple  blossoms,  lilacs  and  syringas  of  May, 
roses  and  grapes  of  June,  honeysuckle  and  moonflowers, 
cinnamon  vine  and  mignonette  of  summer,  and  the  spicy, 
health-giving  aroma  of  pines,  firs,  and  spruces  all  the  year. 
And  finally,  our  pictures  will  grow  from  year  to  year,  so  that 
when  Ave  plant  trees  we  must  imagine  ahead  —  ten,  twenty, 
fifty,  one  hundred  years. 

Trees.  Given  the  ground,  the  first  thing  to  plan  is  the  posi- 
tion and  grouping  of  the  trees.  In  order  to  do  this  intelli- 
gently we  must  know  the  biology  of  the  different  species  — 
the  soil  in  which  each  grows  best,  and,  especially  for  our  future 
pictures,  the  height  and  spread  and  general  form  and  color 
of  each. 

For  outdoor  laboratory  work  measure  the  height  and  spread 
to  scale  and  sketch  the  general  form  of  ten  specimen  trees  of 
different  kinds.  These  data  will  be  needed  in  determining  the 
distances  apart  at  whicli  different  trees  are  to  be  planted  in 
the  following  plans  of  residence  lots,  parks,  and  streets.  Ar- 
range, by  committee  of  the  class  or  otherwise,  to  have  all  the 
trees  of  the  district  studied  so  that  notes  of  the  class  may  be 
combined  into  a  table  like  that  on  page  82,  which  shall  give 
the  planting  data  for  all  the  native  and  horticultural  trees 
available  for  the  locality. 

We  need  to  develop  clear  ideas  of  these  dimensions  in  order 
to  avoid  the  common  mistakes  of  planting  trees  too  near  the 
house  and  too  close  together.  In  the  one  case  the  trees  cause 
dampness  and  decay  about  the  home,  and  in  the  other  they 
grow  into  crowded  jumbles  rather  than  into  beautiful  pictures. 

After  learning  the  individual  trees  we  may  next  study 
effective  grouping  as  presented  both  in  natural  woodlands  and 
in  specimens  of  artificial  planting  in  the  neighborhood.  Select 
some  of  the  finest  groups  available  and  analyze  into  component 


82 


CIVIC)  BIOLOGY 


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HOME  PLA>s^TING  AND  LANDSCAPE  GAEDENING     83 

trees;  measure  distances  apart  and  draw  the  ground  plan  to 
scale,  and  sketch  or  photograph  the  groups. 

Rules  for  grouping  trees  are  sometimes  given.  The  follow- 
ing are  modified  from  different  authorities  as  suggestive  and 
practical. 

1.  Specimen  trees  —  those  which  stand  alone  —  should  be 
chosen  for  special  beauty  or  character ;  oaks,  chestnuts,  black 


Fig.  38.  A  specimen  of  nature's  planting 

walnuts,  old  pines,  and  cedars  for  massive  strength  and  dig- 
nity; hemlock,  elm,  larch,  and  spruce  and  the  birches  for 
graceful  tracery  of  form  and  outline ;  Colorado  blue  spruce, 
purple  beech,  Schwedler,  swamp  and  Japanese  maples  for  rich 
coloring. 

2.  Groups  should  not  be  too  compact,  and  on  estates  of 
limited  extent  are  generally  more  effective  if  made  up  of  trees 
of  different  characters.  They  should  he  unsymmetrical,  irreg- 
ular, "  natural "  in  form.  The  taller  trees  should,  of  course, 
occupy  the  center,  or  form  the  background  in  boundary-line 


84  CIVIC  BIOLOGY 

groups.  There  is  opportunity  here  for  fine  contrasts  in  form, 
color,  and  character  —  oak  and  weeping  willow  or  American 
elm,  birches  against  white  pine,  etc. 

3.  Plant  trees  or  groups  to  screen  objectionable  features  of 
the  landscape,  and  leave  open  spaces  toward  all  pleasing  views. 

4.  Plant  deciduous  trees  on  the  south  and  west  of  the  house 
for  summer  shade  and  winter  sunshine,  and  evergreens  along 
the  northerly  side  to  serve  as  stormbreaks  in  winter. 

Shrubs.  Given  the  bounds  and  main  features  in  tastefully 
planted  trees,  the  shrubbery  lets  the  picture  down  naturally 
to  the  ground,  and  supplies  much  desired  color  and  fragrance. 
Shrubs,  too,  more  than  anything  else  form  the  setting  for  the* 
house,  fit  it  to  the  eartli,  and  make  it  a  part  of  the  landscape. 
The  house  being  the  center  of  the  general  scheme,  we  should 
place  the  choicest  shrubs  nearest  to  it. 

For  outdoor  laboratory  work  study  throughout  the  fall  and 
spring,  at  least,  good  specimens  of  all  the  different  ornamental 
shrubs  to  be  found  in  your  local  parks  or  neighborhood. 
Observe  them  in  all  possible  relations  to  trees,  buildings,  and 
other  shrubs,  so  that  you  will  be  able  to  choose  the  shrubbery 
of  a  park  or  the  home  grounds  with  intelligent  taste. 

A  local  planting  table  like  that  suggested  for  the  trees 
should  be  made,  giving  size,  form,  preferred  exposure,  and 
color  and  season  of  bloom.  A  selection  of  shrubs  may  be  made 
which  will  furnish  bloom  for  cutting  and  fine  color  effects  in 
either  flower  or  fruit  for  not  only  the  growing  season  but  the 
entire  year.  If  it  is  desired  to  combine  use  and  ornament,  — 
a  tendency  growmg  in  favor, — nothing  in  the  way  of  shrubber}' 
can  be  more  effective,  either  in  bloom  or  fruit,  than  the  dwarf 
fruit  trees,  especially  peach,  apricot,  nectarine,  cherry,  pear, 
and  apple.  Lists  and  descriptions  of  desirable  shrubs  for  the 
locality  can  be  obtained  from  any  good  nursery  catalogue. 

''  American  trees  and  shrubs  for  American  homes  "  is  a  rule 
with  exceptions,  but  one  that  has  much  good  sense  in  its  favor. 


Fk;.  81),  Mission  iijrape.    Larijest  grapevine  in  the  world 
Planted  in  1842,  in  1895  bore  over  ten  tons  of  grapes,  Carpinteria,  California 


Fig.  40.  Delaware  grape 
Living  decoration  for  a  dining  porch 

85 


86 


CIVIC  BIOLOGY 


What  exotic  is  more  beautiful  than  our  mountain  laurel  or 
our  rhodora,  or  more  graceful  than  our  sumacs  and  elder- 
berry, or  sweeter  than  our  pepper  bush  and  wild  rose?  It 
is  no  slight  matter  that  a  plant  has  become  adjusted  to  its 
environment  on  a  large  continent  through  the  many  centu- 
ries of  its  struggle  for  existence. 

Flowers.    With  slu-ubbery  now  as  the  background  come 
naturally,  in  the  finest  landscape  effects,  the  hardy  perennials 


Fig.  41.   The  most  beautiful  back  door 
in  Worcester,  Massachusetts 


Fig.  42.  An  ugly  back  door 
Compare  with  Fig.  41 


—  peonies,  lilies,  irises,  hollyhocks  and  phloxes,  goldenrods 
and  asters,  and  a  host  of  others;  also  the  annual  bedding 
plants,  the  cannas  and  dahlias,  sunflowers,  marigolds  and 
zinnias,  nasturtiums,  sweet  peas  and  flowering  beans,  and  by 
all  means,  here  and  there,  a  few  tuberoses  and  a  bed  of  helio- 
trope and  mignonette.  These  supply  the  finishing  touches  for 
both  color  and  fragrance,  and  should  be  studied  largely  as  a 
matter  of  individual  preference  and  taste.  Here  is  the  test, 
however,  for  harmonious  and  pleasing  effects  in  color,  and, 
since  we  must  live  with  our  homes  so  much  of  the  time,  the 


HOME  PLANTING  AND  LANDSCAPE  GAEDENING     87 


whole  effect  should  be  restful  and  comfortable  and  as  far 
removed  from  fussiness  as  possible. 

Vines.  Especially  on  the  house  and  buildings,  vines  add  a 
touch  of  comfort,  as  well  as  wildness  and  grace,  without  which 
few  pieces  of  landscape  gardening  are  complete.  Vines  of  all 
plants  are  also  the  most 
plastic,  convenient,  and  ac- 
commodating. With  them 
we  may  have  shade  of  any 
degree  anywhere  we  wisli, 
cover  anything,  from  a  snag, 
post,  or  rock  to  a  factory 
wall,  and  we  may  have  fra- 
grance and  flowers  and  even 
fruit  thrown  in  for  good 
measure. 

As  suggested  for  the 
trees  and  shrubs,  make  a 
special  study  of  all  the 
vines  adapted  for  home 
and  park  planting  in  your 
locality,  and  include  meth- 
ods of  propagating  and  cul- 
ture of  each. 

The  world  over,  the  grape 
combines  in  highest  degree 
all  the  best  qualities  of  both 
use  and  beauty.  The  way 
our  American  wild  grapes  climb  the  tallest  forest  trees  shows 
that  with  proper  support  they  may  be  carried  to  any  reason- 
able height.  A  growth  of  sixty-three  feet  of  vine  from  a 
single  bud  in  a  season  proves  how  quickly  any  extent  of 
wall  can  be  shielded  from  the  hot  sun  of  summer  by  prop- 
erly trained  grapevines.    For  covering  surface  no  other  vine, 


Fig.  43.  California  grapes 

Photograph  by  George  C.  Husmann,  United 
States  Department  of  Agriculture 


88 


CIVIC  BIOLOGY 


excepting  possibly  the  Actinidia,  can  compare  with  the  grape, 
if  well  established.  The  fact  that  it  climbs  by  tendrils  makes  it 
much  easier  to  train,  prune,  and  control  than  vines  which  twine 
around  their  supports.  The  grape  thrives  in  poor  soil,  wet  or 
dry,  and  can  be  depended  upon  to  flower  and  fruit  for  centuries, 
renewing  its  youth  often  from  the  root.  Varieties  differ  much 
in  form  and  size  of  leaf  and  in  vigor  and  rapidity  of  growth. 
Make  a  special  study,  with  sketch  to  scale,  of  at  least  one 
good  specimen  vine  before  it  is  pruned  back  in  the  fall.    Note 

variety,  age,  size,  and  height 
of  main  stem  and  length 
of  several  of  the  most  vig- 
orous canes  of  the  season's 
growth.  Record,  if  possible, 
the  amount  of  fruit  pro- 
duced. By  each  member  of 
the  class  selecting  a  differ- 
ent variety,  the  grapes  best 
suited  to  the  locality  may 
be  compared  and  learned. 
Houses,  even  in  crowded 
cities,  might  be  transformed 
into  bowers  of  shade  and 
beauty  by  the  adequate  use  of  the  grape  alone. 

Aetinidia  arguta  is  a  close  second  of  the  grape.  After  be- 
coming well  established  it  is  a  most,  rampant  grower,  speedily 
reaching  the  tops  of  the  tallest  trees,  and  about  buildings  is 
likely  to  require  severe  pruning.  The  leaves  are  clean  and 
glossy,  with  red  petioles.  Fragrant  and  attractive  flowers 
appear  in  June,  and  the  fruit  ripens  in  September  and  October. 
This  is  a  dull  green  drupe  the  size  of  a  small  plum,  with  a 
flavor  and  quality  quite  unlike  anything  American.  The  Aeti- 
nidia comes  to  us  from  Japan  and  is  hardy  and  well  adapted 
to  our  climate.    Along  with  other  valuable  importations  from 


Fig.  44.    Flowers  of  Aetinidia 


HOME  PLANTING  AND  LANDSCAPE  GARDENING  89 


the  same  source  it  has  the  advantage  of  not  being  attacked 
by  American  insect  pests.    Rom  rugosa^  the  Japanese  quince, 
and  the  Japanese  snowball  are  other  cases  in  point. 
Following  are  some  problems  in  landscape  gardening : 

1.  Make  a  series  of  sketches,  to  scale,  of  your  home  grounds, 
—  ground  plan  and  at  least  one  view,  —  naming  and  locating 
all  trees,  sln-ubs,  vines, 
and  bedduig  plots  with 
their  contents. 

2.  Draw  a  ground 
plan  and  view  of  your 
home  grounds  as  you 
Avould  wish  to  have 
them. 

8.  Can  you  suggest 
any  improvements  in 
the  street  tree  planting 
of  your  town,  city,  or 
neighborhood  ?  Draw 
plans  and  specifications 
for  special  local  prob- 
lems of  this  kind  — 
the  treatment  of  certain 
streets  or  roadsides. 

4.  Let  each  member 
of  the  class  sketch  a 
ground  plan  and  view 


Fig.  45.    Actinidia  arguta 

Two  vines,  three  years  from  transplanting, 

afford  dense  shade  for  a  porch 


of  the  school  grounds,  giving  both   specifications  and  cost. 

5.  Taking  a  local  public  square,  park,  common,  or  play- 
ground as  a  special  problem  for  analysis  and  study,  can  you 
suggest  improvements  in  its  planting  ? 

The  simplest  principles  of  landscape  gardening  are  often 
alluded  to  as  the  "  ^,  B,  C "  of  the  subject.  They  are  based 
upon  the  pleasing  arrangement  of  trees,  vines,  and  shrubs  and 


90 


CIVIC  BIOLOGY 


open  glades  as  found  in  beautiful  bits  of  natural  woodland. 
A.  Leave  open  glades  for  air  and  sunshine.  They  make  even 
modest  grounds  seem  roomy.  B.  Plant  in  masses,  like  the 
forms  of  clouds,  leaving  open  vistas  toward  sunrise  and  sun- 
set and  all  pleasing  views,  and  covering  unsightly  features 

of  the  landscape.  C.  Avoid 
straight  rows ;  Nature  never 
plants  that  way. 

Finally  we  may  study  home 
and  city  planting  as  an  invest- 
ment. If  well  done,  probably 
no  equal  expenditure  will  re- 
sult in  larger  returns.  Figure 
out  increased  value  of  property 
along  well-planted  streets  and 
in  the  vicinity  of  public  parks. 
Let  each  member  of  the  class 
study  and  analyze  his  own 
home  with  this  point  in  view 
—  figuring  into  the  account 
iirst  cost,  yearly  expenditures, 
and  upkeep  against  enhanced 
values.  A  shade  tree  in  the 
wrong  place  may  be  a  positive 
injury  to  a  home,  while  the  same  tree  in  tlie  right  place  might 
enhance  its  value  a  hundred,  or  even  a  thousand,  dollars.  And 
in  these,  as  in  all  similar  cases,  it  is  not  the  money  values  we 
are  studying  so  much  as  the  human  health  and  comfort  which 
they  represent. 

The  planning  and  planting  of  a  home  or  a  country  beauti- 
ful enough  to  inspire  the  love  of  a  people  is  no  unimportant 
matter.  Compare  Russia  and  Japan  with  this  feature  in  view 
and  in  connection  with  the  results  of  the  recent  war. 


'^-B 

Fig.  46.    Adinidia  arguta  in  fruit 


CHAPTER  IX 

PRACTICAL   BIOLOGY    OF    AGRICULTURAL    PRODUCTION 
AND  CIVIC  UTILIZATION  OF  LAND 

Public  prosperity  is  like  a  tree :  agriculture  is  its  roots ;  industry  and  com- 
merce are  its  branches  and  leaves.  If  the  root  suffers,  the  leaves  fall,  the 
branches  break,  and  the  tree  dies.  —  Chinese  saying,  from  Hopkins,  ''Soil 
Fertility  and  Permanent  Agriculture  " 

In  final  analysis  civilizations  rest  mainly  upon  agricultural 
efficiency.  At  least,  this  must  be  increasingly  true  as  civiliza- 
tion advances.  In  this  vital  matter  it  is  high  time  to  cast 
aside  all  pride  and  conceit  and  wake  up  to  a  sense  of  our 
low  agricultural  efficiency  as  a  people.  In  1907  a  total  of 
20,000  square  miles  of  agricultural  land  in  Japan  supported 
46,977,003  people,  or  2349  people  to  the  square  mile,  with 
less  than  one  dollar  per  capita  excess  of  agricultural  imports 
over  exports.  Fertile  regions  of  both  China  and  Japan  sup- 
port as  high  as  3840  people  per  square  mile.  Compare  these 
figures  with  those  for  Belgium,  the  most  densely  populated 
country  in  Europe ;  here  less  than  300  people  per  square 
mile  are  supported.  The  best  farming  districts  of  the  LTnited 
States  support  about  30  people  per  square  mile. 

Further,  in  little  more  than  a  brief  century  we  have  swept 
over  a  continent  rich  in  the  accumulated  fertility  of  many 
thousands  of  years,  and  in  ignorance  have  wasted  and  depleted 
("  mined  "  rather  than  "  cultivated  ")  the  soil.  As  land  in  one 
region  has  been  mined  out,  we  have  abandoned  it  and  moved 
to  virgin  fields,  but  now,  with  practically  no  more  new  land 
available,  we  are  forced  to  turn  toward  the  more  civilizing 
and  socially  ethical  task  of  permanent  American  agriculture. 

91 


ujmuiu^mMUMmmM^^i^jMJM^^ 


THE  EFFECT  OF  THOROUGH  CULTIVATION  UPON  THE  FARMER'S 
OWN  MIND.  AND  IN  REACTIONTHROUGH  HIS  MIND  BACK  UPON  HIS  BUSI- 
NESS, IS  PERHAPS  QUITE  EQUALTO  ANY  OTHER  OF  ITS  EFFECTS.  EVERY 
MAN  IS  PROUD  OF  WHAT  HE  DOES  WELL,  AND  NO  MAN  IS  PROUD  OF  THAT 
HE  DOES  NOT  WELL.  WITH  THE  FORMER  HIS  HEART  IS  IN  HIS  WORK, 
AND  HE  WILL  DO  TWICE  AS  MUCH  OFIT  WITH  LESS  FATIGUE  ;  THE  LAT- 
TER HE  PERFORMS  A  LITTLE  IMPERFECTLY.  LOOKS  AT  IT  IN  DISGUST, 
TURNS  FROM  IT,  AND  IMAGINES  HIMSELF  EXCEEDINGLY  TIRED -THE 
LITTLE  HE  HAS  DONE  COMES  TO  NOTHING  FOR  WANT  OF  FINISHING. 

HAVE  SO  FAR  STATED  THE  OPPOSITE  THEORIES  OF  "MUD- 
SILL" AND  "FREE  LABOR,"  WITHOUT  DECLARING  ANY  PREFER- 
ENCE OF  MY  OWN  BETWEEN  THEM.  ON  AN  OCCASION  LIKE  THIS,  I 
OUGHT  NOT  TO  DECLARE  ANY.  I  SUPPOSE,  HOWEVER,  I  SHALL 
NOT  BE  MISTAKEN  IN  ASSUMING  AS  A  FACT  THAT  THE  PEOPLE 
OF  WISCONSIN  PREFER  FREE  LABOR,  WITH  ITS  NATURAL  COMPANION,   EDUCATION. 

THIS  LEADS  TO  THE  FURTHER  REFLECTION  THAT  NO  OTHER  HUMAN  OCCUPATION  OPENS  SO  WIDE 
A  FIELD  FOR  THE  PROFITABLE  AND  AGREEABLE  COMBINATION  OF  LABOR  WITH  CULTIVATED  THOUGHT, 
AS  AGRICULTURE.  I  KNOW  NOTHING  SO  PLEASANT  TO  THE  MIND  AS  THE  DISCOVERY  OF  ANYTHING 
THAT  IS  AT  ONCE  NEW  AND  VALUABLE  -  NOTHING  THAT  SO  LIGHTENS  AND  SWEETENS  TOIL  AS  THE 
HOPEFUL  PURSUIT  OF  SUCH  DISCOVERY.  AND  HOW  VAST  AND  HOW  VARIED  A  FIELD  IS  AGRICULTURE 
FOR  SUCH  DISCOVERY!  THE  MIND,  ALREADY  TRAINED  TO  THOUGHT  IN  THE  COUNTRY  SCHOOL,  OR 
HIGHER  SCHOOL,  CANNOT  FAIL  TO  FIND  THERE  AN  EXHAUSTLESS  SOURCE  OF  ENJOYMENT.  EVERY 
BLADE  OF  GRASS  IS  A  STUDY  ;  AND  TO  PRODUCE  TWO  WHERE  THERE  WAS  BUT  ONE  IS  BOTH  A  PROFIT 
AND  A  PLEASURE.  AND  NOT  GRASS  ALONE,  BUT  SOILS,  SEEDS,  AND  SEASONS  -  HEDGES,  DITCHES, 
AND  FENCES -DRAINING,  DROUGHTS.  AND  IRRIGATION  -  PLOWING,  HOEING,  AND  HARROWING- 
REAPING,  MOWING  AND  THRESHING  -  SAVING  CROPS,  PESTS  OF  CROPS,  DISEASES  OF  CROPS,  AND 
WHAT  WILL  PREVENT  OR  CURE  THEM  -  IMPLEMENTS,  UTENSILS.  AND  MACHINES,  THEIR  RELATIVE 
MERITS,  AND  HOW  TO  IMPRO.VETHEM  -  HOGS,  HORSES,  AND  CATTLE  -  SHEEP,  GOATS,  AND  POULTRY 
-TREES,  SHRUBS,  FRUITS,  PLANTS,  AND  FLOWERS  -  THE  THOUSAND  THINGS  OF  WHICH  THESE  ARE 
SPECIMENS  -  EACH  A  WORLD  OF  STUDY  IN  ITSELF. 

IN  ALL  THIS,  BOOK  LEARNING  IS  AVAILABLE.  A  CAPACITY  AND  TASTE  FOR  READING  GIVES  ACCESS 
TO  WHATEVER  HAS  ALREADY  BEEN  DISCOVERED  BY  OTHERS.  IT  IS  THE  KEY.  OR  ONE  OF  THE  KEYS,  TO 
THE  ALREADY  SOLVED  PROBLEMS.  AND  NOT  ONLY  SO  :  IT  GIVES  A  RELISH  AND  FACILITY  FOR  SUC- 
CESSFULLY PURSUING  THE  UNSOLVED  ONES.  THE  RUDIMENTS  OF  SCIENCE  ARE  AVAILABLE.  AND 
HIGHLY  AVAILABLE.  SOME  KNOWLEDGE  OF  BOTANY  ASSISTS  IN  DEALING  WITH  THE  VEGETABLE  WORLD 
-WITH  ALL  GROWING  CROPS.  CHEMISTRY  ASSISTS  iN  THE  ANALYSIS  OF  SOILS,  SELECTION  AND 
APPLICATION  OF  MANURES,  AND  IN  NUMEROUS  OTHER  WAYS.  THE  MECHANICAL  BRANCHES  OF  NATU- 
RAL PHILOSOPHY  ARE  READY  TO  HELP  IN  ALMOST  EVERYTHING,  BUT  ESPECIALLY  IN  REFERENCE  TO 
IMPLEMENTS  AND  MACHINERY. 

THETHOUGHT  RECURS  THAT  EDUCATION  -  CULTIVATED  THOUGHT-  CAN  BEST  BE  COMBINED  WITH 
AGRICULTURAL  LABOR,  OR  ANY  LABOR,  ON  THE  PRINCIPLE  OF  THOROUGH  WORK  ;  THAT  CARELESS, 
HALF  PERFORMED,  SLOVENLY  WORK  MAKES  NO  PLACE  FOR  SUCH  COMBINATION;  AND  THOROUGH 
WORK,  AGAIN.  RENDERS  SUFFICIENT  THE  SMALLEST  QUANTITY  OF  GROUND  TO  EACH  MAN;  AND 
THIS,  AGAIN.  CONFORMS  TO  WHAT  MUST  OCCUR  IN  A  WORLD  LESS  INCLINED  TO  WARS  AND  MORE 
DEVOTED  TO  THE  ARTS  OF  PEACE  THAN  HERETOFORE.  POPULATION  MUST  INCREASE  RAPIDLY.  MORE 
RAPIDLY  TH\N  IN  FORMER  TIMES,  AND  ERE  LONG  THE  MOST  VALUABLE  OF  ALL  ARTS  WILL  BE  THE 
ART  OF  DERIVING  A  COMFORTABLE  SUBSISTENCE  FROM  THE  SMALLEST  AREA  OF  SOIL.  NO  COM- 
MUNITY WHOSE  EVERY  MEMBER  POSSESSES  THIS  ART,  CAN  EVER  BE  THE  VICTIM  OF  OPPRESSION  IN 
ANY  OF  ITS  FORMS.  SUCH  A  COMMUNITY  WILL  BE  ALIKE  INDEPENDENT  OF  CROWNED  KINGS,  MONEY 
KINGS,  AND  LAND  KINGS. 

IT  IS  SAID  AN  EASTERN  MONARCH  ONCE  CHARGED  HIS  WISE  MEN  TO  INVENT  HIM  A  SENTENCE  TO  EE 
EVER  IN  VIEW,  AND  WHICH  SHOULD  BE  TRUE  AND  APPROPRIATE  IN  ALL  TIMES  AND  SITUATIONS. 
THEY  PRESENTED  HIM  THE  WORDS.  "AND  THIS.  TOO,  SHALL  PASS  AWAY."  HOW  MUCH  IT  EX- 
PRESSES! HOW  CHASTENING  IN  THE  HOUR  OF  PRIDE!  HOW  CONSOLING  IN  THE  DEPTHS  OF  AFFLIC- 
TION! "AND  THIS,  TOO,  SHALL  PASS  AWAY."  AND  YET,  LET  US  HOPE,  IT  IS  NOT  QUITE  TRUE.  LET 
E'~n  US  HOPE,  RATHER,  THAT  BY  THE  BEST  CULTIVATION  OF  THE  PHYSICAL  WORLD  BENEATH  AND  AROUND 
^  US,  AND  THE  INTELLECTUAL  AND  MORAL  WORLD  WITHIN  US,  WE  SHALL  SECURE  AN  INDIVIDUAL.  SO- 
§{  CIAL,  AND  POLITICAL  PROSPERITY  AND  HAPPINESS.  WHOSE  COURSE  SHALL  BE  ONWARD  AND  UPWARD, 
1^  AND  WHICH.  WHILE  THE  EARTH  ENDURES.  SHALL  NOT  PASS  AWAY.  -ANNUAL  ADDRESS  BEFORE  THE 
S  WISCONSIN  STATE  AGRICULTURAL  SOCIETY,  AT  MILWAUKEE.  WISCONSIN.  SEPTEMBER  30,  1859. 
^      ABRAHAM  LINCOLN,  "COMPLETE  WORKS,"  VOL.1,  P.  579  FF. 


I 

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92 


BIOLOGY  OF  AGRICULTURAL  PRODUCTION      93 

Agricultural  efficiency.  Wherever  possible  let  each  member 
of  the  class  choose  some  local  plant  or  anunal  industry  and 
collect  records,  establish  working  standards,  and  figure  out  the 
local  percentage  of  efficiency.  This  might  well  form  the  main 
thesis  work  of  the  year,  and,  in  a  connnunity  in  which  agricul- 
ture is  important,  by  distributing  theses  to  cover  the  different 
crops  we  may  make  this  work  contribute  to  civic  advancement. 
A  recent  estimate  by  Emerson  yields  the  following  results : 

SrANDAUDS  AND  Percentagp:  of  Efficiency  von 
Following  Chops 


Standard  Yield 

AVEKAOK 

PeuCentof 

Annual  Loss  bv 

PKR  ACKK 

Yield 

Efficiexcy 

Low  Efficiexcv 

Potatoes 

500  bu. 

96  bu. 

19 

$900,000,000 

Wheat 

50  bu. 

14  bu. 

28 

1,000,000,000 

Cotton 

1  bale 

0.35  bale 

35 

1,000,000,000 

Corn  ^ 

lOObu.  (record  239  bu.) 

28  bu. 

28 

2,680,000,000 

Oats  1 

100  bu.  (record  209^  bu.) 

32  bu. 

32 

585,413,000 

The  standard  of  500  bushels  of  potatoes  per  acre  is  ad- 
mittedly low.  l^y  the  mere  addition  of  brains  (''  cultivated 
thought ")  U)  breeding  and  selection  of  variety,  and  scientific 
precision  in  fertilizers  and  culture  methods,  this  standard 
might  be  raised  to  1000  bushels,  possibly,  without  increasing 
per-acre  cost  of  operation,  except  to  pick  up  the  additional 
500  bushels.  Probably  Lord  Rosebery  holds  the  world's 
record :  2053  bushels  of  potatoes  —  1754  marketable  and  299 
bushels  of  culls  per  acre.  AVith  the  standard  at  2000  bushels 
our  scale  of  efficiency  falls  to  4 1  per  cent. 

Hills  of  potatoes  vary  remarkably  in  the  same  field,  and 
beginnings  have  been  made  in  *'  hill  selection  "  of  seed  on  this 
account.  Tubers  planted  from  strong  hills  have  thus  been 
found  to  yield  as  high  as  sixteen  times  as  many  pounds  as 

1  Data  obtained  elsewhere. 


94 


CIVIC  BIOLOGY 


tubers  from  weak  hills  of  the  same  variety.  Little,  however, 
has  been  done  by  way  of  recording  the  yields  of  single  hills. 
Grubb  gives  16  tubers,  weighing  8  pounds,  as  the  ideal  hill 
in  field  culture.    Perry  Nathan  Pickett,  aged  twelve  years,  in 

connection  with  his  industrial 
project  work  in  Salem,  Ore- 
gon, in  1914,  produced  a  rec- 
ord hill  of  Burbank  potatoes, 
containing  1 3  large  and  2  small 
tubers,  weighing  l6  pounds. 
A  record  hill  from  Lexington, 
Oregon,  yielded  24  pounds, 
and  Carl  Gabrielson,  aged 
eleven,  Puyallup,  Washing- 
ton, has  reported  a  volunteer 
hill  in  his  school  garden 
that  dug  103  potatoes,  rang- 
ing from  12  ounces  to  the  size 
of  a  hen's  egg  and  weighing 
40  pounds  12  ounces.  If  we 
know  how  to  raise  one  hill 
best,  we  may  extend  this 
knowledge  to  any  number 
of  hills.  Hence,  for  an  ele- 
mentary standard  unit  the 
single  plant  will  be  a  more 
usable  one  than  the  plot  or 
acre.  Any  boy  can  find  a 
place  to  raise  one  or  ten  hills 
of  potatoes ;  he  may  try  a  different  experiment  on  each  hill, 
and  thus  learn  more  from  a  single  hill  than  he  might  from 
an  acre.  The  same  is  true  of  a  single  plant  of  wheat,  corn, 
tomato,  cabbage,  lettuce,  strawberry,  blackberry,  raspberry, 
grape,  peach,  apple,  pear,  rose,  lily,  or  anything  else. 


Fig.  47.  Growth  race  between  potatoes 

Potatoes  weighed  186.7  and  9.8  g.  At  eud 
of  fifty-eight  days  the  roots  had  growu 
8640  ft.  and  155  ft.  respectively.    Photo- 
graph by  Frances  W.  Tufts 


BIOLOGY  OF  AGEICULTUEAL  PRODUCTION      95 

It  is  interesting  that  Lincoln  should  state  the  problem  so 
clearly,  more  than  fifty  years  ago.^ 

My  first  suggestion  is  an  inquiry  as  to  the  effect  of  greater  thorough- 
ness in  all  departments  of  agriculture  than  now  prevails  in  the  North- 
west—  j)erhaj)s  I  might  say  in  America.  To  sj^eak  entirely  within 
bounds,  it  is  known  that  fifty  bushels  of  wheat,  or  one  hundred  bushels 
of  Indian  corn,  can  be  produced  from  an  acre.  Less  than  a  year  ago  I 
saw  it  stated  that  a  man,  by  extraordinary  care  and  labor,  had  produced 
of  wheat  what  was  equal  to  two  hundred  bushels  from  an  acre.  But 
take  fifty  of  wheat,  and  one  hundred  of  corn,  to  be  the  possibility,  and 
compare  it  with  the  actual  crops  of  the  country.  ]\Iany  years  ago  I  saw 
it  stated,  in  a  patent-office  report,  that  eighteen  bushels  was  the  average 
crop  throughout  the  United  States  ;  and  this  year  an  intelligent  farmer 
of  Illinois  assured  me  that  he  did  not  believe  that  the  land  harvested 
in  that  State  this  season  had  yielded  more  than  an  average  of  eight 
bushels  to  the  acre;  much  was  cut  and  then  abandoned  as  not  worth 
threshing,  and  much  was  abandoned  as  not  worth  cutting.  As  to  Indian 
corn,  and  indeed,  most  other  crops,  the  case  has  not  been  much  better. 
For  the  last  four  years  I  do  not  believe  the  ground  planted  with  corn 
in  Illinois  has  produced  an  average  of  twenty  bushels  to  the  acre. 

Lincoln  admits  too  much  for  the  sake  of  argument,  however, 
when  he  says : 

Unquestionably  it  will  take  more  labor  to  produce  fifty  bushels  from 
an  acre  than  it  will  to  produce  ten  bushels  from  the  same  acre  ;  but  will 
it  take  more  labor  to  produce  fifty  bushels  from  one  acre  than  from 
five?  Unquestionably  thorough  cultivation  will  require  more  labor  to 
the  acre ;  but  will  it  require  more  to  the  bushel  ? 

Recent  experiments  have  proved  that  less  labor,  rather  than 
more,  may  produce  the  larger  crop.  Goethe's  proverb,  Nichts 
ist  schrecklicher  als  tdtige  Unwissenheit,  "  Nothing  is  more  ter- 
rible than  active  ignorance,"  applies  with  unusual  force  to  the 
delicate  task  of  raising  a  plant  best. 

The  most  laborious  and  expensive  factor  in  growing  a  field 
of  corn  has  been  "thorough  cultivation."   After  this  had  been 

1  Abraham  Lincoln,  Complete  Works,  Vol.  I,  p.  577. 


96  CIVIC  BIOLOGY 

tearing  off  half  the  roots  of  the  corn  plants  for  centuries, 
and  laboriously  reducing  the  yields  from  30  to  50  or  more 
busliels  per  acre,  some  one  hit  upon  the  idea  of  studyhig  — 
applying  ''  cultivated  thought "  to  the  roots  of  the  shigle  corn 
plant.  It  was  discovered  that  many  of  them  spread  out  near 
the  surface,  five,  six,  or  even  seven  feet  in  every  direction. 
Next  came  the  thought,  May  not  too  deep  cultivating  injure 
these  roots  ?  The  experhnent  has  now  been  tried  of  shaving 
tlie  weeds  without  stirring  the  soil  at  all,  applying  careful 


Fig.  48.   Two  plots  of  corn  on  peaty  swamp  land 

Left,  fertilized  with  phosphorus  (not  needed) ;   crop,  0.    Right,  fertilized  with 

potassium;  crop,  72  hushels  per  acre.    Seed,  cost  of  fertilizer,  aud  labor  on  the 

two  plots  about  equal.    Photograph  by  Cyril  G.  Hopkins 

shallow  tillage  to  comparable  rows  in  the  same  fields.  Results 
have  shown,  on  the  average,  equal  yields  from  the  uncultivated 
rows.  Figure  out,  for  your  farm,  township,  county,  state,  or 
for  the  United  States,  how  many  dollars'  worth  of  labor  this 
one  discovery  may  save  annually. 

Pure-bred  selected  strains.  Again,  we  have  learned  that  by 
breeding  and  selection  of  productive  strains  the  crop  may  be 
increased  without  additional  labor.  This  fact  gives  the  added 
value  to  pure-bred  stock  in  animals  and  plants.  Half  the  plants 
in  an  ordinary  field  of  potatoes  or  corn  may  be  ''loafers";  half 
the  trees  in  an  ordinary  orchard  may  be  "  resters  " ;  half  the 


BIOLOGY  OF  AGRICULTURAL  PR0I>UCT10N      97. 

hens  or  cows  in  the  ordinary  barnyard  may  be  ''  boarders.*'  A 
single  specimen  of  plant  or  animal  may  produce  a  phenomenal 
yield,  but  the  progeny  may  revert  to  loafers  and  boarders. 
Pure-bred  strains  have  been  carefully  selected  for  generations, 
until  all  bad  heredity  has  been  weeded  out  and  the  progeny 
can  be  relied  upon  to  be  thoroughbreds,  that  is,  to  yield  a 
uniform,  standard  result.  Collect  records  of  various  pure-bred 
strains  in  the  neighborhood  and  compare  yields,  as  below : 

DiFFERENCKS  IN   YiELD   DuE  TO  YaUIETY,  EXPERIMENT  STATION, 

RosTERN,  Canada 


Yield 

Weight 

Time  to 

Unmarket- 

I'EB Acre 

PER  Bushel 

Mature 

able 

Huron  wheat 

73  bu. 

59  lb. 

107  days 

Marquis  wheat     .... 

70  bu. 

61  11). 

98  days 

Kubanka  wheat    .... 

37  bu. 

52  11). 

107  days 

Reeves'  Rose  potato     .    . 

623  bu. 

46  bu. 

American  Wonder  potato 

371  bu. 

58  bu. 

Disease-resisting  strains.  A^ariation  applies  to  immunity 
from  disease  as  well  as  to  any  other  character,  and  hence  the 
Avorld  is  bemg  searched  for  strains  of  animals  and  plants  which 
have  developed  resistance  to  prevailing  diseases.  Cattle  from 
India  are  being  introduced  into  the  south,  because  they  are 
immune  to  Texas  fever.  The  ordinary  Crimson  Rambler  rose 
is  much  infested  with  mildew,  while  Van  Fleet's  seedhng  is 
practically  immune  to  it.  Such  innnunity  may  extend  even  to 
freedom  from  insects,  as  sliown  by  many  foreign  introductions, 
notably  Bosa  rugosa  and  the  floAvering  quince  and  snowball 
from  Japan.  Thus  in  all  sorts  of  epidemics  it  is  of  great  im- 
portance to  note  any  immune  individuals,  and  these  should 
be  carefully  preserved  with  a  view  to  development  of  resistant 
strains.    Collect  the  data  on  any  local  work  along  this  line. 

A  good  case  in  point  occurred  recently  in  the  cabbage  industry 
of  southeastern  Wisconsin.    A  fungus  suddenly  appeared  w^hich  took 


98 


CIVIC  BIOLOGY 


practically  the  entire  crop.  The  Agricultural  Department  at  Madison 
was  appealed  to  for  help,  and  the  experts,  on  visiting  the  infested  terri- 
tory, found  here  and  there  a  cabbage  plant  that  had  not  been  attacked. 
Seed  was  saved  from  these  specimens  and  a  resistant  strain  secured. 
Another  example  is  the  resistance  of  mazzard  stock  to  cherry  gummosis. 

Problem  of  soil  fertility.  Fifteen  chemical  elements  com- 
monly enter  into  or  constitute  the  plant  body.  They  are  natu- 
rally the  most  abundant  elements  of  air,  water,  and  earth. 
Take,  for  example,  the  composition  of  corn : 


Per  Cent 

Oxygen  .     , 

46.000^ 

Carbon  .     . 

45.000  ► 

Hydrogen   . 

6.400^ 

Nitrogen     . 

1.760^ 

Phosphorus 

.300  - 

Potassium  . 

.340  J 

Magnesium 

.125' 

Calcium 

.022 

Iron  .     .     . 

.008 

Sulfur     .     . 

.004 

Silicon   . 

.014   ■ 

Sodium  .     . 

.013 

Chlorin  .     . 

.013 

Aluminium 

Manganese 

Total  . 

99.99  1 

Elements  obtained  in  abundance  from  air 
and  water. 

Elements  that  the  corn  plant  must  get  from 
the  soil,  and  that  we  must  buy  if  they  are 
deficient. 


Elements  seldom  lacking  in  the  soil  in  the 
small  amounts  required,  except  calcium, 
which  in  regions  free  from  limestone  is 
often  added  to  "  sweeten,"  or  correct  acid- 
ity in,  soils. 


An  acre  of  soil  6J  inches  deep  weighs  2,000,000  pounds, 
and  if  we  analyze  this  and  determine  how  many  pounds  of 
the  necessary  elements  it  contains,  and  if  we  know  how  many 
pounds  of  these  elements  are  removed  in  a  given  crop,  we  can 
figure  roughly  how  long  the  soil  will  ''  last,"  that  is,  be  able 
to  produce  the  crop.  Hopkins  has  done  this  in  the  table  on 
the  following  page.^ 


■^  Of.  Hopkins,  Soil  Fertility  and  Permanent  Agriculture,  p.  13. 
2  Ibid.,  p.  59. 


BIOLOGY  OF  AGRICULTURAL  PRODUCTION      99 
Relative  "Supply  and  Demand"  of  Seven  Elements 


Essential  Plant-Food 
Elements 

Pounds  in  2,000,000 
Pounds  of  Aver- 
age Soil 

Pounds  IN  100 

Bushels    of 

Corn 

Years  Sup- 
ply     WILL 
last 

Phosphorus  

Potassium 

Magnesium 

Calcium "  . 

Iron 

Sulfur "... 

2,200 
49,200 
48,000 
68,800 
88,600 

2,200 

17 
19 

7 

n 

130 

2,600 

7,000 

55,000 

200,000 

10,000 

Nitrogen  (virgin  N.W.  soil)i  . 
Nitrogen  (in  air  over  acre)  i     . 

6,936 
70,000,000 

'             69 
100           ,     700,000 

Of  course  the  problem  is  not  as  simple  as  this  table  would  indicate, 
because  these  elements  are  being  returned  to  the  soil  in  various  ways 
from  the  air  and  from  the  decay  of  plants  and  from  animal  wastes.  The 
table  does  show  what  tends  to  happen  in  the  ordinary  process  of  deple- 
tion from  continuous  cropping,  if  care  is  not  taken  to  thus  return  the 
needed  elements  to  the  soil. 

The  three  absolutely  essential  elements  which  are  likely  to 
limit  productivity  of  a  soil  are  nitrogen,  phosphorus,  and  po- 
tassium. Nitrogen,  the  most  vital  of  all,  does  not  exist  in 
combination  as  a  mineral  in  the  soil,  but  must  be  added  from 
the  decay  and  waste  matters  of  animals  and  plants  or  by  bac- 
terial action.  Of  the  other  two,  phosphorus  is  likely  to  be  the 
limiting  element,  but  potassium  compounds,  as  well  as  those 
of  calcium,  are  so  easily  soluble  that  they  are  likly  to  be 
completely  leached  away,  as  was  the  case  in  the  peaty  loam 
soil  (Fig.  48).  No  matter  what  the  abundance  of  the  others, 
lack  of  any  essential  element  limits  plant  growth ;  it  is  like  a 
storehouse  full  of  food,  with  the  key  lost.  This  is  well  shown 
in  the  Maryland  Experiments  with  Lime.^ 

1  Added  to  table  from  p.  559. 

2  Cf .  Hopkins,  Soil  Fertility  and  Permanent  Agriculture,  p.  167. 


100  CIVIC  BIOLOGY 

Produce  in  Eleven  Years,  per  Acre 


Bushels  of  Corn 
IN  Four  Crops 


Bushels  of  Wheat 
IN  Three  Crops 


Tons  OF  Hay  IN 
Four  Crops 


No  lime 

Ground  shells  (2500  lb.) 


98 
145 


32 
43 


2.60 
4.29 


Learn  the  results  of  local  experiments  in  fertilizing  land 
and  collect  all  available  records  and  data  on  local  soil  analyses 
and  surveys.  The  possible  value  of  sucli  work  is  well  demon- 
strated in  the  following  from  the  Oswego  Experiments  with 
strawberries : 

Rich  Bottom  Land,  Season  fairly  Di;v  (1897) 

Plat  I :     ooO  lb.  dissolved  rock  per  acre  ;  yield,  13,597  (]t. 
Plat  II  :  700  11>.  dissolved  rock  per  acre ;  yield,  20,0(30  (]t. 
(An  expense  of  $7.00  made  a  gain  of  $358.55  over  Plat  J.) 

Value  of  land.  Some  land  may  be  dear  as  a  gift.  Agricul- 
tural nitrogen  is  worth  $0.15  a  pound,  potassium  $0.06,  ground 
limestone  $0,005,  and  phosphorus  $0.03.  At  these  prices  let  us 
compare  the  values  of  twT)  samples  of  land. 

Pounds  in  2,000,000  Pounds  of  Soil 


Plant  Food 

ALVNITOBA 

Vali'e 

Bavarian  Barrens 

Value 

Phosphorus    .    .    . 
Potassium  .... 
Nitrogen     .... 
Calcium     .... 

2,530 
17.100 
20,100 
27,000 

$75.90 
1,020.00 
3,015.00 

135.00 

Trace 
None 
Trace 
1380 

$0.00 
0.00 
0.00 
6.90 

Total  values  ...... 

$4,241.90 

$6.90 

Of  course,  beyond  a  certain  limit  additional  amounts  of  any 
plant  food  may  not  be  of  immediate  value,  but  the  above  fig- 
ures indicate  a  fundamental  reason  for  the  rush  of  agricultural 
emigration  to  the  northwest.    Still,  with  all  the  experience  of 


BIOLOGY  OF  AGRI€tTL'rUK-Aa:;:BR9]5^l]CXlOX    101 

the  past  with  exhausted  and  abandoned  soils,  the  people  on 
these  rich  lands  are  again  talking  of  the  "  inexhaustible  fer- 
tility" of  the  soil,  and  burning  their  straw  and  manure  or 
hauling  the  latter  onto  the  ice  to  befoul  their  streams.  A 
comparison  of  virgin  soil  in  the  Canadian  Northwest  with  soil 
adjoining  it  which  had  been  cultivated  twenty-two  years 
showed  a  loss  of  nitrogen  per  acre  from  6936  to  4736  pounds, 
or  2200  pounds,  a  loss  of  |330.00  worth  of  nitrogen  per  acre. 


Fertility  Contained  in  Different  Farm  Crops 
(Approximate  maximum  amounts  removable  per  acre  annually) 


Pounds 

Pkodick 

YlKLD 

NiTROtiKX 

Pho.sphohus 

POTASSrUM 

Yam  i; 

Corn,  grain     .    .    . 

100  bu. 

100 

17 

19 

116.65 

Stalks,  cobs    .    .    . 

3T. 

50 

H 

54 

10.93 

Corn  crop  .     .    . 

150 

m 

73 

27.58 

Wheat,  grain      .    . 

.50  bn. 

71 

12 

13 

11.79 

Straw 

2iT. 

25 

4 

45 

6.-57 

Wheat  crop    .     . 

96 

16 

58 

18.36 

Alfalfa  hay     .    .    . 

8T. 

4001 

36 

192 

72.60 

Cotton  lint      .    .    . 

1,000  lb. 

3 

.4 

4 

.70 

Cotton  seed    .    .    . 

2,000  lb. 

63 

11 

19 

10.92 

Cotton  stalks      .    . 

4,0001b. 

102 

18 

59 

19.38 

Cotton  crop    .     . 

168 

29.4 

82 

31.00 

Potatoes      .... 

.300  bu. 

63 

13 

90 

15.23 

Apples 

600  bu. 

47 

5 

57 

10.62 

Leaves 

4T. 

59 

7 

47 

11.88 

Wood  growth      .    . 

Jq  of  tree 

6 

2 

5 

1.26 

Apple  crop     .     . 

112 

14 

109 

23.76 

Fat  cattle   .... 

1,0001b. 

25 

7 

1 

4.02 

Fat  hogs     .... 

1,0001b. 

18 

3 

1 

2.85 

Milk   ...... 

10,0001b. 

57 

7 

12 

9.48 

Butter 

4001b. 

0.8 

0.2 

0.1 

.14 

1  Much  of  this  nitrogen  is  taken  from  the  air,  and  the  roots  go  so  deep  that 
even  the  phosphorus  and  potas.sium  may  be  largely  supplied  from  layers  of 
soil  below  the  reach  of  other  crops. 


102  ■:  ':  ^  r*  "'?  r' V  CIVIC  .BIOLOGY 

Losses  in  plant  food  due  to  cropping.  Too  many  have  not 
counted  the  cost  of  a  crop  to  Mother  Earth,  and  hence  have 
taken  it  as  a  free  gift,  with  no  thought  of  making  any  return. 
The  table  above,  modified  from  Hopkins,^  shows  wliat  a  few 
typical  crops  actually  take  from  the  soil. 

Complexity  of  the  problem.  It  remains  to  add  that  the  prob- 
lem of  soil  fertility  is  much  more  complicated  than  the  above 
brief  statement  would  seem  to  indicate.  Warren  says :  "  The 
fertile  surface  soil  may  be  carried  away  by  erosion,  by  wind, 
or  water.  Probably  more  soil  fertility  is  lost  in  this  way  than 
by  cropping."  ^  So  the  humus  may  be  exhausted,  and  with  it 
the  soil  may  lose  its  power  to  hold  moisture,  so  that  it  becomes 
hard  and  dry,  and  plant  food  in  any  amounts  is  of  no  avail.  Or 
soil  may  be  too  wet  and  require  drainage,  and  too  free  drain- 
age may  rapidly  leach  away  nitrates,  potash,  and  lime.  Chem- 
ical changes  are  going  on  within  the  soil,  and  additions  are 
being  made  to  it  from  the  air,  which  lead  some  authorities  to 
claim  that  mineral  plant  foods  are  practically  inexhaustible. 
Poisonous  substances,  it  is  claimed,  are  excreted  by  the  roots 
of  certain  plants,  so  that  proper  rotation  of  crops  is  all  that  is 
needed  to  maintain  fertility  indefinitely.  That  is,  the  soil  is 
"  A  bank  account  which  requires  for  its  maintenance  only  the 
rotation  of  the  check  book  among  the  members  of  the  family!" 
Hopkins  sums  up  the  whole  matter  as  follows : 

The  possible  enormous  and  irreparable  damage  of  such  teaching  lies 
in  the  fact  that  even  our  remaining  supply  of  good  land  will  ultimately 
be  depleted  .  .  .  beyond  the  point  of  self-redemption,  thus  repeating  the 
history  of  our  abandoned  Eastern  lands,  where  the  rotation  of  crops  was 
the  common  rule  of  practice  for  more  than  a  hundred  years. 

Problems  in  animal  industry.  Perhaps  the  most  important 
dairy  records  are  those  of  Professor  Fraser  of  the  University  of 
Illinois.  He  tested  554  cows  in  36  commercial  dairy  herds,  each 

1  Soil  Fertility  and  Permanent  Agriculture,  p.  154. 

2  Farm  Management,  p.  184. 


BIOLOGY  OF  AGRICULTURAL  PRODUCTION    103 

for  a  full  year.  The  best  25  per  cent  produced  301  pounds  of 
butter  fat  per  year  ;  the  lowest  25  per  cent  only  133.5  pounds. 
He  concludes  from  the  experiment  as  follows :  "  If  it  costs  $30 
a  year  to  feed  the  poorer  cows  and  $38  a  year  to  feed  the  better 
ones,  then  at  present  prices  a  herd  of  25  of  the  better  will 
produce  as  much  net  profit  as  would  1000  of  the  poorer  cows." 
The  Hoi  stein,  Banostine  Belle  de  Kol,  held  the  world's 
record  for  butter  fat  in  1912  — 1058  pounds  in  one  year. 


By  courtesy  of  the  Ohio  Farmer 

Fig.  4U.    Banostine  Belle  de  Kol 

According  to  above  figures,  five  such  cows  would  yield  the 
net  product  of  25  of  the  better  dairy  cows,  and  their  calves 
might  be  worth  even  more  for  breeding  purposes.  The  highest 
dairy  record  for  1913  is  1073  pounds  of  butter  fat,  scored  by 
May  Rilma,  a  Guernsey.  And  so  progress  in  every  branch  of 
agriculture  becomes  a  game  which,  if  well  played,  may  ever 
"  lighten  and  sweeten  toil." 

Poultry  offers  perhaps  the  most  practicable  field  for  ele- 
mentary experiments  in  the  breeding  and  care  of  animals,  and 


104 


CIVIC  BIOLOGY 


any  branch  of  the  industry,  from  pigeons  and  chickens  to  geese 
and  turkeys  and  native  game  birds,  is  Ukely  to  yield  a  sub- 
stantial profit  from  the  start.  One  of  the  chief  problems  of 
present  interest  is  that  of  breeding  for  egg  production,  the 
accepted  unit  being  the  number  of  eggs  laid  in  a  year.    Some 

recent  American    records    are 

shown  in  the  table  below. 

Variations  in  growth  of  flesh 
or  fat  are  similar  to  those  in 
milk  and  egg  production.  This 
means  that  one  animal  may 
not  digest  or  assimilate  food 
as  well  as  another,  or  one  may 
use  its  energy  in  developing 
nervous  activity  (which  is  not 
edible)  while  the  other  is  grow- 
ing flesh  and  fat.  Experiments 
have  shown  that  one  animal 
may  thus  require  over  30  per  cent  more  food  to  gain  a  pound 
of  flesh  than  another.  Here  selection  and  thorough  breeding 
are  saving  enormous  losses  and  increasing  productive  efliciency. 

Amkricax  Egg  Records 


Fig.  50.    Hen  C.  521 

Bred  by  Professor  James  Dryden, 
Corvallis,  Oregon 


Year 

Number  of  Eggs 

Description  of  Hex 

IftlO 

282 

Barred  Plymouth  Rock,  Agricultural 
College,  Guelph,  Ontario 

1911 

281 

White  Plymouth  Rock,  Lady  Showy  on, 
Illinois 

1912-101.3 

30.3 

Hen  C.  521,  cross  between  white  Leg- 
horn and  barred  Plymouth  Rock. 
Reared  at  the  Oregon  Agricultural 
College,  Corvallis,  Oregon  ^ 

1  This  is  held  to  be  the  world  record  up  to  date.  In  attempting  to  make 
a  record  of  this  kind  it  is  necessary  to  have  official  control  to  guard  against 
any  possible  mistakes  or  falsification,  if  the  records  are  to  stand. 


BIOLOGY  OF  AGRICULTUKAL  PRODUCTION    105 

Special  problems.  Keep  the  record  of  a  cow  and  figure  profit  or  loss 
on  basis  of  cost  of  feed  and  care.  Trai>nest  a  fiock  of  hens  and  study 
variation  in  egg  production,  making  results  the  basis  for  future  breeding 
and  improvement  of  flock. 

Try  different  chemicals  or  fertilizers  in  strips  across  the  rows  in 
the  garden,  to  discover  special  needs  of  soil  or  crop. 


Fig.  51.   Growth  and  oppor- 
tunity 

Oue  of  the  8  carrots,  thinned 
to  4  to  the  foot,  which  weighed 
11  pounds,  and  the  smallest 
of  50  carrots,  unthinned  and 
standing  25  to  the  foot,  which 
weighed  1.7  jiounds 


Fig.  52.    Parsnips  show- 
ing result  of  a  hard  spot 
in  the  row 


Experiment  with  different  consistency  of  soil :  trench  a  strip  two  or 
three  feet  deep,  dynamite  a  strip,  or  even  leave  a  hard  strip  across  the 
garden,  in  order  to  study  differences  in  production  due  to  tillage  (Fig.  52), 
and  thin  plants  to  different  distances  (Fig.  51). 

Test  seeds  of  all  kinds  before  planting  in  garden  or  field.  By  blow- 
ing off  the  light,  small  seeds  and  planting  the  5  or  10  per  cent  of  the 
heaviest  and  strongest  seeds,  crops  of  remarkable  vigor  and  evenness  are 


106  CIVIC  BIOLOGY 

secured.  Saving  seed  from  strong,  productive  plants — potato,  wheat,  corn, 
cotton,  timothy — has  given  rise  to  a  large  increase  of  production  without 
other  change  or  difference  in  method  of  cultivation. 

In  order  to  unite  the  work  of  the  school  with  the  interests  of  the 
community,  offer  to  test  all  kinds  of  seeds,  especially  corn,  if  in  a  corn- 
raising  section.  An  increase  of  from  30  to  40  per  cent  in  the  corn  crop 
of  the  district  has  resulted  from  such  testing. 

A  most  remarkable  fact  has  developed  with  reference  to  seed  potatoes. 
Immature  tubers,  about  half  or  two  thirds  grown  or  ripened,  may  pro- 
duce twice  as  many  potatoes  as  dead  or  so-called  overripe  seed  from  the 
same  field.  Immature  seed  potatoes  are  specially  raised  and  saved  in 
Europe,  and  this  one  factor  may  account  for  the  great  difference  in  favor 
of  European  over  American  yields  —  more  than  2000  bushels  per  acre 
as  compared  with  less  than  1000  as  the  best  American  record.  This 
must  be  a  matter  of  activity,  or  vigor,  of  buds,  or  of  availability  of  the 
starch  food  supply.  For  information  on  raising  seed  potatoes,  write  your 
state  experiment  station. 

Work  for  record  production  of  thoroughly  cultivated,  pure-bred,  pedi- 
gyefe  single  plants  —  the  world-record  hill  of  potatoes,  the  best  plant  of 
corn,  wheat,  cotton,  oats,  sunflower,  tomato,  cabbage,  currant,  raspberry, 
blackberry,  grape,  peach,  plum,  cherry,  apple,  etc.  More  may  be  learned 
from  intensive  practical  study  of  a  few  plants,  each  of  which  is  a  special 
experiment,  than  from  any  number  of  less  intelligently  cultivated  acres. 

In  all  such  problems,  with  both  animals  and  plants,  we  neied 
to  learn  all  we  can  about  the  laws  and  forces  of  heredity, 
breeding,  and  breeds,  and  also  all  we  can  about  favorable  en- 
vironment, feeding,  care,  and  treatment.  The  former  topics  are 
treated  further  in  the  appropriate  chapters.  The  latter  should 
be  made  subjects  of  special  study  whenever  it  is  possible  to 
have  the  care  of  either  an  animal  or  a  plant,  and  to  secure  an 
authentic  record.  Any  one,  by  applying  "  cultivated  thought," 
may  render  a  world  service  by  winning  a  new  world  record. 


CHAPTER  X 

INSECT  TYPE  PROBLEMS:  IMPORTANT  FLIES 

If  each  egg  of  the  common  house  fly  should  develop,  and  each  of  the 
larvae  should  find  the  food  and  temperature  it  needed,  w^ith  no  loss  and  no 
destruction,  the  people  of  the  city  in  which  it  happened  would  suffocate 
under  the  plague  of  flies.  — Jordan  and  Kellogg,  "  Evolution  and  Animal 
Life,"  p.  59 

And  as  for  the  typhoid  fly,  that  a  creature  born  in  indescribable  filth 
and  absolutely  swarming  with  disease  germs  should  be  practically  invited 
to  multiply  unchecked,  even  in  great  centers  of  population,  is  surely  nothing 
less  than  criminal.  — L.  O.  Howard 

What  flies  do.  During  the  Spanish- American  war  typhoid 
fever  wounded  20,738  United  States  soldiers  and  killed  1580. 
The  chief  means  of  spreading  this  infection  were  the  swarms 
of  flies  which  infested  the  army  encampments.  To  emphasize 
this  menace  to  health,  Dr.  Howard  has  suggested  that  we 
change  the  name  of  the  house  fly  to  tyjyhoid  fly.  This  opened 
the  way  for  thorough  investigation  of  the  insect,  and  its  filthy 
habits  were  soon  found  to  render  it  the  possible  distributor 
for  many  other  filth-disease  infections.  Tuberculosis,  cholera, 
enteritis  (including  epidemic  dysentery  and  cholera  infantum 
—  the  fly-time  "summer  complaint"  of  infants),  spinal  menin- 
gitis, bubonic  plague,  smallpox,  leprosy,  syphilis,  gonorrhea, 
ophthalmia,  and  the  eggs  of  tapeworms,  hookworm,  and  a  num- 
ber of  other  parasitic  worms  - —  for  all  these  and  many  more  the 
fly  has  been  discovered  to  be  a  ready  actual  or  potential  carrier. 
Since  the  fly  is  proved  to  be  such  an  active  agent  of  transmis- 
sion between  all  manner  of  filth,  on  which  it  feeds  and  in  which 
it  breeds,  and  human  foods,  Dr.  Stiles,  of  the  Hookworm 
Commission,  has  proposed  to  call  it  the  filth-disease  fly. 

107 


Fig.  53,   Flytraps  for  barnyard  or  stable  window 

1,  first  model  as  found  after  being  set  one  week ;  2,  same,  emptied  by  lifting  off 
top  frame ;  trap  lifted  from  bottom  board  to  indicate  construction ;  3  and  4,  larger 
window  trap,  showing  construction  and  in  position.  The  small  traps  in  3  are 
merely  to  take  off  samples  of  the  catch  for  analysis.  These  traps  are  made  to  fit 
the  window  about  which  flies  naturally  congregate,  gunny  sacks  are  hung  over 
the  other  windows  to  darken  them  and  to  flap  in  the  wind,  and,  when  properly 
placed  and  managed,  one  trap  will  catch  practically  all  the  house,  stable,  horn, 
lilack,  bot,  and  blow  flies  and  even  the  mosquitoes  that  try  to  get  in  <tr  (^>ut,  or 
that  either  feed  or  breed  about  the  stable 
108 


IMPORTANT  FLIES 


109 


First  necessary  step  in  health  conservation.  The  most  sig- 
nificant fact  in  the  situation  is  that  only  by  eliminating  the 
fly  can  we  form  any  notion  of  how  much  present  sickness  it 
is  causuig.    On  this  account  health  oiftcers  everywhere  are 


The  figure  may  be  supposed  to 
represent  a  model  I'J  inches  wide, 
12  inches  tall,  and  10  inches  thick 
—  a  convenient  size  for  ordinary 
use  in  a  city  yard.  The  speciti- 
cations  Avill  then  be  :  two  end 
boards  J  inch  or  I  inch  thick, 
12x  10  inches ;  four  strips  for  the 
top  frame,  Ix  i  inch,  two  12  inches 
and  two  9  inches  long ;  Avire  for 
top  frame,  10  x  12  inches  (raw 
edges  folded  over  ^  inch);  two 
top  shoulder  strips  Ix^  inch,  11 
inches  long ;  four  bottom  strips 
I  inch  thick  and  12  inches  long, 
two  §  inch  wide  and  two  1  inch 
wide ;  screen  Avire  for  sides  and 
bottom  in  one  piece,  12  inches 
wide  and  41  inches  long  (allow 
1  inch  to  fold  over  raAV  ends, 
J  inch  each) 


Fig.  54.    Cross  section  and  detail  of  stable-window  or  barnyard  flytrap 

These  traps  may  be  of  any  convenient  size,  to  suit  conditions,  and  may  be  made 
of  box  boards,  strips,  and  screen  wire.  It  is  Avell  to  plan  to  use  wire  of  standai-d 
widths.  If  used  on  the  ground,  the  traps  may  be  made  without  the  trap-folds  in 
the  sides,  Avhich  do  most  of  the  catching  when  the  trap  is  set  in  a  stable  Avindow. 
Fold  the  wive  squarely  at  the  angles  indicated  in  the  figure.  A,  D,  C,  J),  K,  F,  G,  and 
at  these  points  snip  in  5  inch.  Fold  the  5-inch  flaps  to  a  right  angle,  turning  them 
in  directions  indicated  by  small  hooks  along  the  course  of  the  wire  (dotted  line). 
This  allows  the  bottom  ridge  and  the  trai>-folds  to  drop  smoothly  inside  the  end 
boards,  and  the  flaps  are  tacked  to  the  end  boards  to  help  hold  the  wire  in  place 
and  make  the  trap  absolutely  fly  tight  so  far  as  any  cracks  along  the  corners  are 
concerned.  The  holes  in  the  s\ure  are  punched  by  pushing  ten  40-penny  wire  spikes 
through  the  exact  apex  of  the  bottom  ridge,  about  1  inch  apart.  If  good  bait  is 
used,  the  flies  may  become  much  crowded  here.  (This  must  be  a  sharp  90°  angle, 
not  a  rounded  dome,  or  the  flies  will  not  find  the  holes.)  Three  holes  are  sufti- 
cient  for  the  side  folds.  Punch  all  these  holes  after  the  wire  is  tacked  in  place. 
The  trap  is  really  as  simple  as  a  box.  AVith  proper  tools  a  boy  ought  to  cut  out  the 
end  boards,  rip  out  the  strips,  nail  up,  fold,  and  tack  the  wire,  all  in  about  one 
hour.  The  main  feature  of  the  trap  is  the  5-incli  crack  opening  upward  to  the  bait 

saying,  in  effect,  ''  Clear  the  air  of  this  universal  distributor 
of  filth,  in  order  that  we  may  be  able  to  trace  other  ways  of  dis- 
ease infection."  Thus  extermination  of  flies  comes  to  be  the 
necessary  first  step  toward  the  effective  prevention  of  disease. 


110  CIVIC  BIOLOGY 

The  evidence  we  have  indicates  that  ahnost  all  dysentery  and 
summer  complaint  (millions  of  cases  and  56,000  deaths  annu- 
ally) are  caused  directly  by  the  house  fly.  One  third  of  the 
typhoid  (about  300,000  cases  and  30,000  deaths)  is  estimated 
to  be  caused  by  flies,  and  an  unknown  and  unknowable  pro- 
portion of  tuberculosis,  spinal  meningitis,  and  other  filth  infec- 
tions. Thus  it  is  quite  possible  that  flies  carry  the  infections 
which  cause  from  70,000  to  100,000  deaths  annually.  About 
2  people  in  the  United  States  die  yearly  from  bites  of  poisonous 
snakes  ;  rabid  dogs  bite  about  100  with  fatal  effect.  Can  you 
think  of  a  more  deadly  animal  than  the  common  typhoid,  or 
filth-disease,  fly  ? 

Spread  of  animal  diseases.  An  additional  factor  is  the  prob- 
able causation  of  disease  among  domestic  animals.  As  they 
are  not  even  partially  protected  by  screens,  and  flies  swarm 
about  their  foods,  epidemics  of  such  diseases  as  fowl  and 
hog  cholera,  bovine  and  fowl  tuberculosis,  and  foot-and-mouth 
disease  are  almost  certainly  spread  by  flies.  This  matter  has 
not  been  investigated  as  it  should  be,  but  we  are  likely  to 
see  a  remarkable  clearing  up  of  animal  diseases  as  soon  as  we 
exterminate  flies  from  our  farms. 

Futility  of  fly  screens.  Finally,  a  minor  consideration  is  the 
(estimated)  $12,500,000  we  pay  annually  for  screen  windows 
and  doors,  which  are  not  only  expensive  but  disagreeable  at 
best.  These  do  not  solve  the  problem,  even  if  they  did  keep 
the  pests  out  of  our  homes.  We  must  prevent  flies  from 
contaminating  foods  on  the  farms  and  in  the  stores  and  mar- 
kets of  our  cities.  Thus  the  fight  against  the  common  enemy 
must  be  community-wide,  and,  since  one  careless  or  ignorant 
household  can  breed  flies  enough  to  infest  all  the  houses  within 
a  quarter  of  a  mile,  positively  every  one  must  cooperate. 

Need  of  universal  cooperation.  The  general  situation,  espe- 
cially the  relations  between  country  and  city,  is  shown  so 
clearly  in  the  following  case  that  we  quote  in  full  from  the 


IMPORTANT  FLIES  111 

Bulletin  of  the  Indiana  State  Board  of  Healthy  July,  1910, 
The  note  is  entitled 

THIS  HAPPENED  IN  INDIANA 

A  few  days  ago  a  physician  in  Martin  County  called  on  the  state 
bacteriological  laboratory  for  Flexner's  antinieningitis  serum.  Dr. 
Simonds  went  to  the  case  and  found  a  seven-months-old  baby  suffering 
from  a  very  severe  gastro-enteritis  with  the  not  infrequently  accom- 
panying meningism.  The  father  of  the  child  was  a  farmer  living  in  a 
four-room  house  with  few  or  no  modern  conveniences.  On  the  wall  of 
the  largest  room  was  a  family-history  chart  done  in  brilliant  colors, 
with  three  columns  of  lines  for  the  record  of  marriages,  births  and 
deaths.  The  parents  had  been  married  ten  years  and  six  children  had 
been  born  to  them.  In  the  death  column  were  the  names  of  four  chil- 
dren, all  under  two  years  of  age.  Another  name  has  since  been  added 
to  this  list. 

The  cause  of  this  sad  story  became  evident  on  inspection.  There 
was  a  shallow  surface  well  in  the  back  yard,  a  short  distance  from  an 
open  privy.  A  large  pile  of  manure  lay  uncovered,  almost  against  the 
side  of  the  barn.  If  this  farmer  had  attempted  so  unthinkable  a  thing 
as  transforming  his  premises  into  a  fly  hatchery  for  commercial  pur- 
poses, he  could  not  possibly  have  achieved  a  more  brilliant  success. 

The  family  and  several  of  the  neighbors  were  eating  dinner  on  the 
back  porch.  Flies  were  swarming  all  over  the  table,  but  showed  a  special 
liking  for  a  particular  dish.  They  were  so  thick  on  this  that  it  was 
absolutely  impossible  to  tell  definitely  what  it  contained  until  one  of 
the  neighbors  swung  her  arm  over  the  table  and  cleared  them  away  long 
enough  for  one,  by  looking  quickly,  to  see  that  the  dish  contained  cot- 
tage cheese.  The  flies  were  so  thick  in  the  house  that  it  was  only  with 
difficulty  that  they  were  fought  away  from  the  field  of  the  spinal  puncture 
and  kept  from  lighting  on  the  instruments. 

On  the  death  certificate  the  cause  of  the  death  of  this  child  was 
doubtless  given  as  "Gastro-enteritis."  It  would  have  been  more  in  keep- 
ing with  the  facts  to  have  said  "  Poisoned  by  Flies." 

Different  kinds  of  flies.  About  43,000  different  kinds  of 
flies  and  related  gnats  and  mosquitoes  have  been  described, 
and  Dr.  Howard  estimates  that  this  group  of  insects  contains 
no  less  than  350,000  species  for  the  whole  world.    One  large 


112 


CIVIC  BIOLOGY 


family,  the  tacliina  flies,  many  of  which  look  much  like  com- 
mon house  flies,  feed  upon  other  insects  and  are  among  our 
most  effective  helpers  m  holding  certain  insects  in  check. 
Tachina  flies  are  being  imported  from  Europe  to  destroy  gypsy 
and  brown-tailed  moths.  Syrphus  flies  are  another  large  family 
which  feed  upon  other  insects.  Tachma  and  syrphus  flies  are 
found  about  rank  vegetation  in  which  other  msects  abound. 
Of  flies  caught  in  and  about  houses  the  typhoid  fly  gener- 
ally numbers  over  90  per  cent.  It  is  distinguished  by  the 
"  elbow "  on  the  fourth  vein  as  it  curves  up  to  the  third 
vein  near  the  tip  of  the  wing  (Fig.  bb}.    The  proboscis  is  an 

extensible  trunk  adapted  for 
lapping  up  liquids,  and  cannot 
be  used  for  either  biting  or 
piercmg.   The  foot  is  provided 


with  claws  for  climbing-  over 


rough  surfaces,  and  also  with 
two  pads  (pulvilli)  covered 
with  sticky,  tubular  hairs, 
which  enable  the  fly  to  walk 
on  ceilings  and  windowpanes. 
No  more  effective  mechanisms 
for  collecting  dust  could  be  designed  than  a  fly's  feet  and 
proboscis,  a  combination  of  six  feather  dusters  and  thirteen 
damp  sponges.  The  constant  "  cleaning  "  movements  of  flies 
are  clearly  designed  to  rub  off  and  scatter  the  adhering  germs 
everywhere  they  go. 

The  ''  little  house  fly  "  (Fan7iia  eanicularis)^  smaller  than  the 
common  fly,  is  often  seen  in  swarms  hovermg  under  chandeliers. 
In  breeding  and  feeding  habits  it  resembles  the  house  fly. 
Other  flies  found  about  houses  are  the  following : 
Bluebottles,  greenbottles,  and  flesh  flies,  or  blowflies,  which 
so  frequently  lay  their  eggs  on  meat.  These  flies  are  scav- 
engers, but  we  can  dispose  of  dead  animals  hi  much  more 


Fig.  55.    Wings   of    {a)   house    fly 

(6)   stable  fly,    (c)  little   house   fly 

{(1)  horn  fly 

Photograph  hy  I.  A.  Field 


IMPORT  AX  T  FLIES 


113 


sanitary  ways  than  by  leaving  them  to  the  blo\\^ies.  Related 
to  these,  and  of  importance  in  the  southern  states,  is  the  screw- 
worm  fly  (  Chrysomyia  macellaria)^  which  oviposits  on  wounds, 
the  maggots  feeding  upon  living  flesh.  These  are  the  flies  that 
sometimes  lay  their  eggs  in  nostrils  or  ears  of  children  or  of 
people  if  asleep  out  of  doors  in  the  daytime,  tlie  maggots 
causing  painful  and  even  fatal  wounds. 

The  stable  fly  (^Stomoxys  calcitrans)^  which  has  somewhat 
the  appearance  of  the  house  fly,  except  that  it  is  provided  with 
a  strong,  piercing  beak,  sucks  the  blood 
of  animals.  This  fly  is  now  convicted 
of  moculating  the  germs  of  infantile 
paralysis  with  .its  bite.  It  also  causes 
great  suffering  to  cattle.  The  smaller 
liorn  fly  (^Hcematohia  serrata^,  imported 
from  Europe  about  1886,  is  another 
bloodthirsty  pest  of  cattle,  biting  both 
by  night  and  day.  It  may  be  recognized 
by  its  habit  of  clustering  in  masses 
around  the  bases  of  the  horns  of  cattle, 
and  may  be  trapped  by  the  method 
recommended  for  the  stable  fly. 

The  black  flies,  deer  flies,  sand  flies, 
and  the  many  botflies  of  horses,  cattle,  and  sheep  are  all  of 
civic  importance  to  the  districts  where  they  abound.     The 
black  flies  of  the  genus  Simtdmm  are  now  under  suspicion 
as  possible  carriers  of  pellagra.    They  breed  in  running  water. 

Life  history  of  the  typhoid  fly.  In  order  to  discover  best 
ways  of  attack,  we  must  study  natural  enemies  from  every 
point  of  view.  The  ease  with  which  mosquitoes  have  been 
exterminated  has  suggested  similar  methods  for  dealing  with 
flies.  But  mosquitoes  breed  only  in  stagnant  water,  which  is 
easily  drained,  filled,  stocked  with  fishes,  or  oiled.  Flies  breed 
in  decaying  filth,  chiefly  in  horse  manure,  but  can  breed  in  any 


Fig.  56.  Stable  flies  that 
a  boy,  with  an  insect  net, 
caught  on  a  cow  in  one  day 


lU 


CIVIC  BIOLOGY 


wet,  fermenting  matter,  animal  or  vegetable.  The  maggots  are 
hard  to  kill ;  they  will  live  for  an  hour  or  more  in  pure  kero- 
sene oil  and  for  over  haK  an  hour  in  alcohol.  Tobacco  kills 
many  insects,  but  house  flies  have  been  bred  from  the  snuff 
on  a  druggist's  counter.  This  means  that  as  long  as  there  are 
flies  about,  they  will  find  something  in  which  to  breed,  and 

that,  with  stables  and  barn- 
yards, gutters,  roadsides, 
and  acres  of  pastures,  with 
accidental  accumulations, 
lawn  clippings,  compost 
and  rotting  weeds  and  fer- 
menting garbage,  preven- 
tion of  breeding  by  doing 
away  with  breeding  places 
and  materials  is  beyond 
human  possibility.  It  is 
easy  in  comparison  to  exter- 
minate the  breeders  them- 
selves. 

Still,  proper  disposal  of  all 
this  waste  matter  comes  to  be 
a  problem  of  greatly  increased 
importance  when  we  attempt  to 
prevent  flies  from  breeding  in 
it.  If  material  becomes  infested 
with  eggs  or  maggots,  the  best 
treatment  of  it  is  probably  to  turn  it  out  in  the  hot  sunshine  and 
dry  it  as  completely  as  possible.  If  this  cannot  be  done,  the  maggots 
may  be  killed  by  saturating  the  material  with  a  solution  of  iron  sul- 
phate (copperas),  two  pounds  to  the  gallon  of  water.  Treatment  of 
stables  with  chloride  of  lime  has  been  recommended,  but  this  is  expen- 
sive and  disagreeable,  and  the  fumes  (chlorin)  are  likely  to  injure  the 
animals.  Stiles  has  buried  infested  material  six  feet  deep  and  found 
that  the  flies  work  their  way  out.  For  the  farm  home  the  cost  of  han- 
dling is  doubled  and  fertilizer  value  reduced  from  55  to  69  per  cent  by 


Fig.  57.    Member  of  Juuiur  !Saiiitary 

Police  of  Cleveland 

Photograph  by  Dr.  Jean  Dawson 


PLATE  II.    LIFE  HISTUKY   UF  THE  GYPSY  INIUTH 

1,  egg  cluster  ;  2,  single  egg  (enlarged  about  four  diameters)  ;  3,  caterpillar; 
4  and  5,  female  and  male  pupae  ;  6  and  7,  female  and  male  moths  ;  8.  im- 
ported lion  beetle  devouring  a  caterpillar.   (All  except  2  about  natural  size.) 


IMPORTANT  FLIES 


115 


antiquated  methods  of  storing,  piling,  and  rotting.  All  stable  waste 
should  be  hauled  and  spread  on  the  land  daily.  It  will  generally  become 
too  dry  for  flies  to  breed  in. 

The  most  expensive  and  disastrous  fallacy  in  this  whole  problem 
is  the  "  fly-tight "  pit  or  receptacle  for  stable  waste.  This  has  been  and 
still  is  recommended  under  the  plausible  excuse,  "  Make  them  fly-tight, 
so  the  flies  cannot  get  in  to  lay  their  eggs."  Eggs  by  the  million  are 
laid  in  the  material  before  it 
is  put  into  the  pit ;  the  tight 
construction  makes  it  an  artifi- 
cially perfected  fly  incubator, 
and  when  it  is  opened,  as  it 
must  be  daily,  the  flies  swarm 
out.  By  this  method  we  actu- 
ally go  to  great  labor  and  ex- 
pense to  breed  more  flies. 

In  cities,  instead  of  fly-tight 
stable  pits,  we  should  have, 
by  city  ordinance,  readily  ac- 
cessible elevated  hoppers  or 
concrete-floored  bins,  and  the 
city  should  arrange  to  empty 
these  clean  to  the  concrete  at 
least  once  a  week  from  May 
to  October.  It  would  be  much 
better,  for  purity  of  air  and 
economy  of  fertilizer,  to  have 
this  done  daily.  By  proper  or- 
ganization of  routes  the  city 
should  be  able  to  gather  and  dis- 
pose of  the  material  at  greatly 
reduced  expense  over  scattering 

and  irregular  private  cleaning.  It  ought  to  be  managed  so  as  to  pay 
stable  keepers  fertilizer  value  of  material,  less  cost  of  handling,  and 
still  deliver  it  regularly  to  gardeners  and  farmers,  as  planned  for,  and 
for  much  less  than  it  costs  to  collect  the  material  privately.  If  this  is 
not  feasible,  then  the  proper  officers  can  license  farmers  and  truck 
gardeners  to  collect  from  specified  stables,  under  contract  to  remove 
the  material  in  the  cleanly  manner  specified  and  at  weekly  intervals. 
Besides  stables,  the  city  should  maintain  strict  supervision  over  all 


Fig.  58.    First  model  of  outdoor  fly  ex- 
terminator 

This  has  been  set  fifty-eight  minutes  and 
has  caught  2000  flies.  It  caught  2  quarts 
(about  16,000)  the  first  day,  aud  might  as 
easily  have  caught  20  quarts  if  they  had 
been  there  to  catch  —  a  vacuum  cleaner  of 
the  air  for  flies.   Designed  by  the  author 


116  CIVIC  BIOLOGY 

stockyards  and  slaughter-houses,  public  dumps,  and  all  industries  which 
handle  materials  likely  to  breed  flies.  It  is  utterly  uncivilized  and 
brutish  that  accumulations  of  filth,  which  allow  flies  to  both  feed  and 
breed,  should  be  permitted  to  vitiate  the  best  efforts  of  thousands  of 
good  people,  cover  their  foods  and  homes  with  filth,  and  cause  not  only 
annoyance  but  disease  and  even  death.^ 

The  eggs  of  flies  hatch  in  about  eight  hours  into  maggots 
which  feed  actively  and  complete  their  growth  hi  six  or  seven 
days.  They  then  burrow  into  the  ground  under  a  manure  pile 
(hence  the  need  of  concrete  floors)  and  transform  into  brown 
puparia,  from  which  they  emerge  as  adult  flies  in  three  days. 

After  coming  out  as  adults  they  fly  about  over  an  area 
not  generally  more  than  one  thousand  yards  in  diameter,  and 
feed  or  drink  from  two  hundred  to  tlu-ee  hundred  times  a 
day  for  from  ten  to  fourteen  days  before  maturing  their  first 
batch  of  eggs.  This  actually  delivers  the  enemy  into  our 
hands.  It  means  that,  with  flytraps  on  every  garbage  can  or 
swill  barrel,  and  with  everythmg  most  attractive  to  flies  very 
carefully  kept  in  these  receptacles,  not  a  single  fly  will  succeed 

1  In  a  large  city  the  writer  found,  opening  on  an  alley,  and  within  a  block 
of  a  great  open  public  market,  a  pile  of  horse  manure,  entirely  unprotected, 
at  least  thirty  feet  in  diameter  at  the  base  and  fourteen  feet  high.  The  outer 
layer  of  this  whole  pile  was  a  solid,  moving  mass  of  housefly  maggots. 
A  moderate  estimate  for  that  pile  would  be  ten  barrels  of  fly  maggots,  which 
would  make,  when  they  reached  their  growth  and  emerged,  from  twenty  to 
thirty  barrels  of  flies.  These  flies  were  swarming  black  over  the  meat  blocks 
and  meats,  fruits,  fish,  candies,  cakes  and  pies  of  the  whole  market.  The 
market  people  (some  few  had  electric  fans)  were  wearing  themselves  out  shoo- 
ing those  flies  from  one  to  the  other  and  back  again.  The  filth  of  that  manure 
pile  was  being  carried  into  thousands  of  homes  with  the  market  supplies. 
The  flies  were  feeding  in  the  market  and  in  hundreds  of  kitchens  in  every 
direction  and  going  back  to  the  manure  to  lay  their  eggs.  It  is  unfair  to 
place  on  the  market  people  the  burden  of  trying  to  protect  their  foods  from 
flies  under  such  conditions. 

The  horses  in  this  large  stable  were  kept  on  the  second  floor  ;  the  manure 
could  have  been  cleaned  into  a  hopper  opening  downward  into  a  dump  cart 
in  the  alley,  and  every  morning  before  daylight,  by  effective  civic  organiza- 
tion of  the  work,  it  might  have  been  out  in  the  country  and  at  work  in  the 
land,  a  paying  proposition  instead  of  an  insufferable  nuisance. 


IMPOKTAKT  FLIES  117 

in  feeding  for  two  weeks  without  getting  caught.  In  this 
case  no  more  eggs  will  be  laid,  and  the  pests  will  vanish. 
Possible  multiplication.  Allowing  ten  days  for  eggs  to 
become  adults,  and,  for  convenience,  ten  days  of  feeding 
between  emergence  and  oviposition,  figuring  that  a  fly  lays 
one  hundred  and  fifty  eggs  at  a  batch  and  lives  to  lay  six 
batches,  compute  the  increase  of  a  pair  of  flies  beginning  to 
lay  May  first.  Half  the  progeny  are  supposed  to  be  females. 
Test  the  following  figures : 

May  10 .     152  flies 

20 ;J02  flies 

aO 11,702  flies 

June  10 ;M,302  flies 

20 911,952  flies 

30 0,484,700  flies 

July  10 72,280,800  flies 

20 325,683,300  flies 

.30 1  5,746,670,500  flies 

The  common-sense  question  is,  Why  not  let  this  pair  of 
flies  catch  themselves  in  May  ?  This  rapid  increase  also  means 
that  anything  short  of  extermination  is  hardly  worth  the  effort. 
A  fly  is  possessed  of  no  more  cunning  than  shot  rolling  down 
a  board,  and  the  last  pair  will  run  into  a  trap  as  easily  as  the 
first.    Why  not  let  them  all  catch  themselves  ? 

Hibernation.  Very  few  house  flies  survive  the  winter  in 
Canada  and  the  northern  states,  and  these  hibernate  as  young 
adults  in  cracks  about  buildings.  They  come  out  of  winter 
quarters  ravenously  hungry  and  feed  for  about  a  week,  at 
least,  before  beginning  to  lay.  If  at  this  critical  time  every 
household  had  some  effective  form  of  outdoor  trap  ready  for 
them,  every  early  spring  breeder  would  be  caught,  and  the 

1  This  last  figure  would  equal  about  143,675  bushels  of  flies  from  one  pair 
in  three  months.  If  we  continue  the  breeding  through  August  and  Septem- 
ber, the  figure  is  1,096,181,249,310,720,000,000,000,000  flies. 


118 


CIVIC  BIOLOGY 


whole  battle  would  be  won  for  the  season.  The  first  commu- 
nity that  does  this  with  absolute  thoroughness,  and  whose 
every  member  is  intelligent  enough  to  realize  the  143,000 
bushels  that  one  pair  might  propagate  in  three  months,  will 
first  be  free  from  the  world-wide,  time-old  plague  of  the 
"  house  fly,  disease  carrier,"  and  from  the  diseases  it  carries. 


1  2  A 

Fig.  59.    Outdoor  fly  exterminator  as  adopted  for  manufacture 

1,  attached  to  garbage  can  (make  hole  in  cover  as  large  as  inside  of  ring,  to  let 

in  plenty  of  light) ;  2,  on  ring  with  which  attachment  is  effected ;  3,  on  its  own 

good-sized  bait  pan.   Designed  by  the  author 

Sketch  a  plan  which  shall  prevent  all  flies  —  typhoid,  stable, 
horn,  and  flesh  flies  —  from  either  feeding  or  breeding  about 
your  own  home.  If  the  fight  is  carried  out  of  doors  into  the 
camps  of  the  enemy,  this  becomes  one  of  the  easiest  problems  to 
solve  in  the  whole  range  of  insect  life,  and  its  solution  com- 
pletely relieves  us  of  the  need  of  screen  windows  and  doors, 
as  far  as  flies  are  concerned;  and,  expense  aside,  screenless 
windows  and  doors  in  summer  are  a  luxury. 


IMPORTANT  FLIES  119 

Study  and  experiment  with  all  the  most  likely  devices  on 
the  market  for  outdoor  fly  extermination,  and  invent  better 
ones  yourself,  if  you  can.  With  the  traps  already  available, 
outdoor  fly  extermination,  as  one  man  who  tried  it  has  said, 
"  is  so  easy  as  to  be  almost  humorous  and  so  effective  (the 
flies  disappear  so  suddenly)  as  to  be  little  short  of  the  uncanny." 


Fig.  60.    "  Getthelastone  "  fly  nets 

The  handles  are  long  enough  to  reach  the  ceiling  without  stretching  and  the  floor 
without  stooping,  enabling  one  to  catch  any  stragglers  that  may  get  by  the  traps 
and  into  the  house.  Make  them  of  finer-mesh  mosquito  net  according  to  directions 
(Fig.  5),  cutting  six  nets  to  the  yard.  Long-handled  swatters  were  tried,  but  they 
too  often  spotted  the  ceilings  and  did  not  prove  as  effective  or  easy  to  use  as  the 
nets.  A  larger  insect  net  is  most  effective  in  exterminating  stable  and  horn  flies 
from  a  dairy.   Designed  by  the  author 

Civic  fly  campaigns.  As  the  fly  problem  becomes  generally 
understood  by  a  community,  the  campaign  comes  naturally  to 
a  dollar-and-cent  basis.  People  will  not  trade  in  fly-infested 
stores,  markets,  or  milk  depots,  or  patronize  hotels  or  res- 
taurants that  are  not  free  from  flies.  For  this  reason  store 
and  restaurant  keepers  must  see  to  it  that  no  fly  feeding  or 
breeding  is  possible  on  their  own  premises,  and  they  must 


120  CIVIC  BIOLOGY 

insist  that  all  their  neighbors  do  likewise.  Thus  general  civic 
cooperation  tends  to  enforce  itself  along  lines  of  financial 
necessity.  Work  out  a  plan  of  campaign  good  enough  to  in- 
sure enlisting  every  home.  In  order  to  give  time  for  discus- 
sion and  publication  of  plans  for  the  active  work  the  following 
spring,  this  should  be  done  in  connection  with  insect  lessons 
in  tlie  early  fall,  when  flies  are  abundant  and  troublesome. 
Killing  the  breeders  in  the  fall  is  as  good  or  better  than  kill- 
ing them  in  the  early  spring,  and  on  one  farm  where  this  was 
done  scarcely  any  flies  appeared  the  next  spring,  wliile  farms 
half  a  mile  away  were  swarming  with  them. 

Nothing  can  take  the  place  of  bringing  the  actual  speci- 
mens into  the  laboratory  and  of  studying  the  flies  and  mag- 
gots as' they  swarm  in  and  about  the  filth  of  outhouses  and 
stables,  gutters  and  spittoons.    If  every  one  could  be  shown, 

—  could  be  made  to  see  and  study  the  flies  as  they  live, 

—  the  community  would  be  in  the  fight  to  a  man,  and  this 
is  all  we  need  for  complete  success.  One  teacher  who  tried 
this  writes: 

Last  week  I  had  some  maggots  in  horse  manure.^  It  was  an  unusual 
thing  to  do  in  school,  but  I  wished  to  emphasize  the  idea  of  filth.  I 
think  it  was  successful,  for  the  disgust  was  great  when  they  saw  that 
they  changed  into  flies.  People  are  so  irresponsible  that  they  have  to 
be  shocked  to  awaken  their  fighting  power. 

Things  to  avoid  in  civic  fly  campaigns.  During  any  season  when 
breeding  is  possible,  avoid  offering  prizes  or  money  enough  to  encourage 
raising  flies.  Also,  never  give  more  than  ten  days  —  the  time  of  a  gen- 
eration—  in  prize  contests  during  the  breeding  season.  A  fortune 
might  be  made  raising  flies  at  ten  cents  a  quart. 

Avoid  delay.  While  spring  is  the  idea]  time  to  start  a  campaign,  one 
begun  in  midsummer  or  even  fall  will  result  in  much  good  and  will  help 
educate  a  community  in  plans  and  methods  for  effective  work  the 
following  season. 

1  This  can  be  done  in  a  safe  and  cleanly  manner  by  means  of  large  bottles. 
They  must  be  stoppered  securely,  as  maggots  are  strong  and  can  burrow  and 
squeeze  through  minute  cracks. 


IMPOKTANT  FLIES  121 

It  has  been  customary  in  many  early  spring  campaigns  to  offer 
children  ten  cents  a  hundred  for  all  house  flies  brought  in  before,  say, 
the  first  of  May,  or  before  breeding  begins  in  the  locality.  On  this 
basis  bills  of  five  or  six  hundred  dollars  may  be  expected  in  good-sized 
cities,  and  it  would  probably  be  better  to  offer  one  cent  a  hundred,  and 
be  sure  to  avoid  paying  for  bluebottles,  greenbottles,  or  other  large  flesh 
flies.  These  will  always  be  killed  along  with  the  rest,  but  they  begin 
active  breeding  much  earlier  in  the  spring  and,  if  not  ruled  out,  might 
easily  swamp  any  treasury.  The  four  flies  whose  wings  are  shown  in 
Fig.  5.5  may  be  included  in  the  list  to  be  paid  for. 

Life  history  of  the  stable  fly.  During  the  summer  of  1912  a  serious 
outbreak  of  stable  flies  occurred  in  grain-raising  sections  of  northern 
Texas,  Oklahoma,  Kansas,  and  Nebraska.  Cows  fell  off  in  milk  and 
even  went  dry,  operations  had  to  be  suspended  in  the  fields  because  the 
animals  could  not  endure  the  torment  of  the  swarms  of  flies,  and  many 
mules,  horses,  and  cattle  were  killed  outright.  Investigation  showed 
that  the  flies  were  breeding  in  the  following  substances,  named  in  approx- 
imate order  of  importance  :  in  the  wet,  fermenting  straw  of  oats,  rice, 
barley,  and  wheat,  and  in  horse  and  cow  manure,  especially  where  mixed 
with  straw.  Thus  most  of  the  trouble  arose  from  decaying  strawstacks 
in  the  fi«^lds  and  from  uncleaned  barnyards.  The  minimal  time  recpiired 
for  the  different  stages  of  development  was  found  to  be :  i^gg,  one  day ; 
larva,  eleven  days ;  pui>a,  six  days ;  making  eighteen  days  from  egg  to 
adult  fly.  Probably  most  of  the  stable  flies  pass  the  winter  in  the  larval 
or  the  pupal  stage  and  so  are  ready  to  emerge  during  warm  spells  in 
winter  and  with  the  first  warm  days  of  spring.  Where  stock  can  be 
stabled,  these  flies  can  be  successfully  caught  in  the  stable  window 
traps  shown  in  Fig.  58. 

Life  history  of  the  horn  fly.  The  horn  fly  breeds  exclusively  in  freshly 
dropped  cow  manure.  The  flies  leave  the  cows  and  swarm  to  fresh  drop- 
pings to  lay  their  eggs,  often  covering  the  material  as  thickly  as  they 
can  stand.  This  occurs  especially  in  the  early  morning  hours,  and  by 
following  the  herd  a  few  mornings  with  a  hand  sprayer  loaded  with 
kerosene  or  any  good  oil  mixture  used  to  keep  the  flies  off  from  ani- 
mals practically  all  the  horn  flies  can  be  killed.  Covering  the  fresh 
droppings  with  lime  also  prevents  the  flies  from  breeding  in  them. 

Health  statistics.  Watch  local  health  statistics  and  re- 
ports, especially  as  to  typhoid  and  cases  and  deaths  from 
summer   complaint,   tuberculosis,   and   pneumonia,   and    any 


122  CIVIC  BIOLOGY 

other  prevalent  filth  infections.  If  the  stable  fly  has  been 
successfully  dealt  with,  compare  the  monthly  reports  on  cases 
of  infantile  paralysis  with  corresponding  reports  of  previ- 
ous years.  1 

Some  people  may  object  to  fly  campaigns  on  the  ground 
that  flies  were  created  for  a  good  purpose.  Any  such  should 
refer  to  Exodus  viii,  31 : 

And  he  [Moses]  removed  the  swarms  of  flies  from  Pharaoh,  from 
his  servants,  and  from  his  people;  there  remained  not  one. 

All  we  ask  is  that  "  there  remain  not  one." 

1  While  the  above  is  passing  through  the  proof  the  discovery  is  announced 
that  maggots  of  flies  (species  not  determined)  which  develop  in  the  bodies  of 
chickens  dying  of  limber  neck  infect  animals  to  which  they  are  fed  with  the 
germs  of  infantile  paralysis,  or  poliomyelitis.  All  such  fowls  should  be  com- 
pletely burned  up.  If  buried,  the  flies  easily  work  their  way  to  the  surface 
and  may  spread  the  infection.  (Latest  evidence  points  to  contact  infection 
by  human  carriers,  and  excludes  any  influence  of  flies  or  other  insects  in 
spreading  this  disease.) 


CHAPTER  XI 

INSECT  TYPE  PROBLEMS:   MOSQUITOES 

Mosquitoes  and  disease.    The  discovery  that  malaria  and 
yellow  fever  are  transmitted  by  certain  mosquitoes  shows  how 


/^ 

\           Al   ^v  ,Ki\  A/ 

^ 

^ 

^           V 

3 

^4^ 

^ 

1 

Ay 

m 

H 

1 

^^L       ^ 

\  i? 

Im 

Fig.  61.   Anopheles  mosquitoes  and  malaria  in  a  city 

A,  Anopheles  mosquitoes  breeding;  dots,  houses  where  malaria  occurs.    There 
would  be  more  dots  in  various  parts  if  there  were  any  houses 

important  a  r61e  an  insect  may  play  in  the  affairs  of  human 
life.  No  obstacles  have  so  seriously  blocked  the  progress  of 
civilization  in  the  tropics  as  these  two  diseases.    The  Panama 

123 


Adults 


esmk^ 


Ficx.  62. 

Left,  Anopheles  (malaria)  ;  center,  Culex  pipienft  (common  nuisance) 
right,  Aeclefi  calopiis  (yellow  fever) 


124 


MOSQUITOES 


12^ 


Canal  has  been  made  possible  mainly  through  the  control  of 
malarial  and  yellow-fever  mosquitoes. 

Of  the  ten  genera  of  mosquitoes  of  North  America,  Anopheles, 
Aedes  (a  e^  dez),  and  Cidex  concern  us  chiefly.  There  are  three 
species  of  Anoph- 
eles distributed 
throughout  the 
country,  and  it 
is  important  to 
remember  that  it 
is  tlu-ough  these 
mosquitoes  only 
that  malarial  fe- 
ver is  spread. 
This  disease  is 
not  as  fatal  as 
some  others,  biit 
is  important  be- 
cause so  widely 
distributed  and 
because  in  ma- 
larial countries 
from  25  to  60 
per  cent  of  the 
people  are  af- 
flicted. In  the 
United  States, 
according  to  the 
estimate  of  Dr. 
1^.  O.  Howard,  there  occur  3,000,000  cases,  causing  a  loss  of 
1100,000,000,  annually.  In  India,  where  the  fever  assumes  a 
fatal  form,  5,000,000  people  have  succumbed  to  it  in  one  year. 

Anopheles  is  particularly  active  during  the  early  part  of  the 
night.    It  may  be  distinguished  from  other  mosquitoes  at  a 


EiG.  63.   Aedes  calopus  —  Yellow-fever  mosciuito 
Egg,  larva,  pupa,  and  adult 


126 


CIVIC  BIOLOGY 


glance  by  its  mottled  wings  and  by  its  posture.  It  resembles 
somewhat  a  thorn  in  the  wall,  standing  as  it  does  at  an  angle 
of  almost  ninety  degrees  to  the  surface,  with  proboscis  in  line 
with  the  body,  whether  the  surface  is  vertical  or  horizontaL 


Jan.    Feb.   Mar.    Apr.    May  June   July    Aug.  Sept.  Oct.    Nov. 

Dec.            1 

1897 
1900 

1895- 

551 

\ 

1896 

Av.462 

1900- 

1898- 

1897- 

1896- 

-1278 

\ 

1897- 

■  828 

\ 

/ 

\ 

1898- 

-138 

/ 

\ 

/ 

\ 

1899- 

-  102 

/ 

\ 

\ 

/ 

\ 

1900- 

-40G 

/ 

I 

\ 

1901- 

■   17   - 

-    5- 

/ 

\ 

/ 

/ 

'  \ 

/ 

\ 

/ 

/ 

/ 

// 

y' 
y' 

v. 

M 

\-- 

\ 

/ 

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, 

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N 

\  \ 

^^_"d 

1896 

^..-- 

,  ,^ 

S 

,„ ,  ^ 

il. 

1898-             1898-  1900-1901- 

Fig.  64.    Yellow  fever  in  Havana 


Aedes  calopus.  This  is  the  mosquito  responsible  for  the 
transmission  of  yellow  fever,  which  in  the  memory  of  man  has 
left  its  dead  unburied  in  some  parts  of  our  country.  Indeed,  in 
the  early  part  of  the  summer  of  1905  a  mosquito  infected  with 


MOSQUITOES 


127 


yellow-fever  blood  came  on  a  cargo  from  Central  America  to 
New  Orleans.  The  fever  spread  rapidly  and  by  the  middle  of 
September  2462  people  had  been  attacked  by  the  disease  and 
329  had  died.  Aedes  is  the  common  rain-barrel  mosquito  of 
the  South ;  it  is  frequently  referred  to  as  the  "  calico  mos- 
quito "  because  of  conspicuous  bandmg  of  its  legs,  thorax, 
and  abdomen  with  black  and  white.  This  mosquito  is  unable 
to  survive  the  winter  of  the  Northern  states  (Fig.  63). 


Fig.  65.    Outdoor  laboratory  work  in  a  malarial  district  of  the  city 


Culex  mosquitoes.  To  this  genus  belong  our  most  common 
household  forms.  They  are  generally  brown  and  may  be  dis- 
tinguished from  Anopheles  by  the  fact  that  they  rest  with  body 
parallel  to  the  plane  of  support  and  head  and  proboscis  bent, 
giving  a  humpbacked  appearance.  While  these  mosquitoes 
are  not  known  to  be  injurious  to  health,  the  annoyance  and 
distress  they  cause  furnish  ample  reason  for  the  general  move- 
ment to  exterminate  them.  Culex  pipiens  is  the  common 
household  pest  throughout  the  country.  Howard  says  these 
mosquitoes  will  not  fly  far  from  their  breeding  places  unless 


128  CIVIC  BIOLOGY 

they  are  carried  bj  light  and  continued  winds.  With  the 
exception  of  two  species  of  Culex  that  breed  in  salt  marshes 
and  migrate  for  long  distances,  mosquitoes  seldom  go  more 
'than  two  hundred  yards  from  where  they  are  hatclied.  In  a 
town  or  city  away  from  these  marshes  the  work  of  extermi- 
nating mosquitoes  is  simple  and  not  expensive.  Indeed,  the 
class  in  civic  biology  can  accomplish  the  task  as  an  interesting 
and  valuable  turn  at  outdoor  laboratory  work.  Before  begin- 
ning the  work,  however,  much  more  should  be  learned  about 
the  habits  and  life  history  of  the  mosquito. 

Habits  and  life  history.  Mosquitoes  are  nocturnal ;  during 
the  bright  part  of  the  day  they  hide  under  leaves,  in  grass,  in 
cellars,  wells,  cisterns,  in  barns,  and  in  the  dark  corners  of  the 
house.  Even  the  "  day  mosquito,"  Aedes^  does  not  fly  about 
or  bite  in  the  bright  sunlight  of  midday.  As  winter  approaches, 
the  female  mosquitoes  seek  dark,  damp  places  in  cellars,  caves, 
hollow  trees,  and  loose  bark  in  which  to  hibernate.  Can  you 
find  them  ? 

Mosquitoes  may  be  distinguished  from  gnats  and  other 
mosquito-like  insects  by  the  presence  of  a  fringe  of  scale-like 
hairs  on  the  margins  of  the  wings." 

Like  many  other  insects,  especially  those  that  suck  blood, 
they  are  strongly  attracted  or  repelled  by  dift'erent  people.  It 
is  a  matter  of  common  experience  that  some  people  are  ainioyed 
by  this  class  of  insects  much  more  than  others.  Odors  like  a 
mixture  of  oil  of  tar,  oil  of  pennyroyal,  and  olive  oil  are  effec- 
tual repellents,  as  is  also  a  mixture  of  cedar  oil  (one  ounce), 
oil  of  citronella  (two  ounces),  spirits  of  camphor  (two  ounces), 
If  an  odor  could  be  discovered  that  is  highly  attractive  to 
mosquitoes,  it  might  be  effective  in  ridding  a  neighborhood  of 
the  pests  if  used  in  connection  with  a  trap  or  some  form 
of  sticky  fly  paper. 

Mosquitoes  seem  to  possess  other  likes  and  dislikes.  They 
are  attracted  to  dark  colors  and  are  repelled  by  lighter  shades ; 


MOSQUITOES 


129 


and  certain  musical  sounds  seem  to  possess  a  charm.  The  song 
of  the  mosquito  varies  with  the  species  and  with  the  sex  ;  it  is 
believed  these  insects  find  their  mates  by  the  pitch  of  their  song. 
Mosquitoes  are  not  without  their  natural  enemies.  Birds 
(especially  nighthawks,  swallows,  and  whippoorwills  flying  at 
dusk),  also  bats  and  dragon  flies,  feed  upon  adult  mosquitoes. 
One  observer  reports  having  found  six  hundred  mosquitoes 


:.i^|^illl 


^ij^* 


mw^^ 


^i^Xy^^..^' 


>2?    I» 


Fig.  66.    Collecting  mosquitoes 
Equipment :  insect  nets  and  smaller  scrim  nets  for  use  in  w  ater 


in  the  crop  of  a  nighthawk.  A  minute  red  mite  may  often 
be  found  clinging  to  mosquitoes,  and  it  is  said  to  greatly 
reduce  their  numbers  in  some  localities. 

Young  mosquitoes  are  aquatic.  Mosquitoes  lay  their  eggs  on 
the  surface  of  water,  usually  about  three  days  after  they  have 
taken  a  meal  of  blood.  The  eggs  are  laid  in  the  early  morning 
hours  and  hatch  into  larvse  about  two  o'clock  the  same  day. 
Oidex  lays  from  two  hundred  to  four  hundred  cigar-shaped 
eggs  which  float  on  end  in  boat-shaped  masses.  The  larvse, 
better  known  as  wrigglers,  swim  actively  about  in  the  water, 


130 


CIVIC  BIOLOGY 


feeding  upon  minute  forms  of  animal  and  vegetable  life  which 
are  swept  into  their  gullets  by  the  constant  motion  of  little 
brush-like  mouth-parts.  A  long  respiratory  tube  comes  from 
the  eighth  segment  of  the  body,  through  which  the  larva 
breathes  by  opening  it  to  the  air.  After  undergoing  three 
different  molts  the  larva  reaches  maturity  and  changes  into  a 
pupa  in  from  ten  to  fourteen  days.   The  pupa  differs  radically 


^ 

~r 

#■ 

-^ 

- 

JLai 

He; 

m 

^  , 

0 

--...  ^..^,.4 

i«|: 

,  :. 

I 

h 

s 

^    '               .     -                 - 

1  >l  ■  - 

J 

lm;%-\,^^ 

^  I  ■'   ■"% 

mm 

"   ':> 

1 

Fig.  67.   Survey  of  mosquito  breeding  places  by  a  normal-school  class 
Equipment  :  bottles,  timiblers,  and  saucers 

from  the  larva  in  appearance,  and  breathes  from  the  ear-like 
organs  on  the  thorax  (Fig.  62).  Except  when  disturbed  the 
pupa  remains  at  the  surface  of  the  water.  After  two  days 
it  splits  down  the  back  and  the  adult  mosquito  rises  from 
the  pupa  skin. 

Anopheles  and  Aedes  lay  their  eggs  scattered  singly,  those 
of  Anopheles  floating  while  the  eggs  of  Aedes  sink  to  the 
bottom  (Fig.  62).  The  larva  of  Aedes  resembles  that  of  Culex^ 
while  that  of  Anopheles  lies  horizontally,  just  under  the  surface. 


MOSQUITOES 


131 


Its  respiratory  tube  is  short,  its  body  black  and  spotted  with 
tufts  of  long  bristles  protruding  from  the  sides  (Fig.  62).  The 
pupae  of  the  different  species  are  not  readily  distinguished. 
Under  favorable  conditions  the  time  required  for  the  eggs  to 
hatch  and  grow  to  adult  mosquitoes  is  ten  days ;  when  the 
weather  is  cold  it  may  be  indefinitely 
extended.  Three  days  after  emergence 
the  adult  may  lay  eggs.  Culex  has  pro- 
duced from  seven  to  ten  generations  in 
a  season  and  Anopheles  four.  Allowing 
150  eggs  to  a  generation,  the  possible 
progeny  of  a  pair  of  Anopheles  in  one 
season  would  be  31,000,000.  The  natu- 
ral enemies  of  immature  mosquitoes  are 
fishes,  newts,  salamanders,  dragon-fly 
nymphs,  the  larvae  of  water  beetles,  and 
even  young  turtles. 

Location  of  breeding  places.  After 
members  of  the  class  have  learned  to 
distinguish  the  different  mosquitoes  and 
their  larvae  at  a  glance,  they  should 
divide  themselves  into  groups  corre- 
sponding to  convenient  divisions  of  the 
district  to  be  studied.  Each  group  should 
be  responsible  for  a  full  report  upon  the 
breeding  places  and  the  kind  of  mosqui- 
toes found  in  its  territory.  Collect  speci- 
mens and  put  the  eggs,  larvae,  and  pupae 
from  each  territory  into  separate  glasses 
or  into  vivaria  with  screen  tops  (Fig.  69).  Keep  a  dish  of 
water  and  a  bit  of  fruit  (apple,  grape,  banana)  in  the  vivaria 
for  the  adults  and  have  green  algae  in  the  water  with  the 
larvae.  Catch  full-fed  mosquitoes  about  animals  or  in  bed- 
rooms  and  keep  in  glasses   arranged  as  shown  in  Fig.  70. 


Fig. 


Insect-catching 
bottle 


For  handling  delicate  in- 
sects this  is  better  than  a 
net.  The  essential  feature 
is  a  paper  cone  opening  in- 
ward through  the  thin  cork 


132 


CIVIC  BIOLOGY 


Watch  for  eggs,  and  examine  the  water  for  larvie.  How 
many  eggs  were  laid  and  how  long  did  they  take  to  hatch  ? 
Wherever  you  have  found  mosquitoes  breeding,  indicate 
it  upon  a  map  of  the  locality  with  letters,  A  denoting  the 
presence  of  Anopheles;  C,  Oulex;  and  Y,  Aedes.  Fig.  61 
shows  the  relation  between  malaria  and  the  Anopheles  mos- 
quitoes as  worked  out  in  this  way  by  a  biology  class. 


Fig.  69.    Vivarium  set  up  for  studying  mosquitoes 
Cheesecloth  top  with  sleeved  opening  and  glass  dish  of  water  in  moss  at  one  end 


Did  you  find  that,  in  general.  Anopheles  breed  by  preference 
in  spongy  bogs  and  stagnant  water,  green  with  algge ;  Aedes  in 
cisterns,  tanks,  buckets,  tubs,  rain  barrels,  flowerpots,  saucers, 
flower  vases,  and  water  pitchers;  Oulex  pipiens  in  ditches, 
stagnant  pools,  catch  basins,  or  in  any  water  near  homes, 
indoors  or  out?  But  algae  may  quickly  change  any  neg- 
lected water  into  a  green  bog  hole  for  Anopheles  to  breed  in. 


MOSQUITOES 


133 


Methods  of  extermination.  It  is  fortunate  for  us  in  our  work 
of  exterminating  mosquitoes  that  they  pass  the  first  three 
stages  of  hfe  in  water,  and  that  the  adults  must  come  to  water 
to  lay  their  eggs,  that  is,  mosquitoes  are  strictly  dependent 
upon  suitable  breeding  waters.  In  all 
successful  campaigns  undesirable  pools 
in  which  mosquitoes  may  breed  have 
been  dramed  or  filled.  Streams  and 
ponds  have  had  their  shores  cleaned  of 
weeds,  brush,  and  stumps,  and  have 
been  graded  so  that  pools  were  not 
left  in  which  mosquitoes  could  breed 
after  freshets  and  storms.  Then  they 
have  been  stocked  with  fishes  which 
feed  upon  the  young  of  mosquitoes.  All 
water  which  was  too  temporary  to  drain 
or  too  polluted  for  fishes  has  been  cov- 
ered with  crude  petroleum  (one  ounce 
to  fifteen  square  feet  of  surface).  This 
treatment  has  been  repeated  as  often  as 
wrigglers  have  appeared.  A  mosquito 
can  walk  on  the  surface  of  water  but  it 
cannot  stand  on  oil ;  hence,  as  all  mos- 
quitoes come  to  the  near-by  water  to  lay 
their  eggs,  they  soon  perish.  Precautions 
have  been  taken  not  to  allow  water  to 
stand  in  tubs,  barrels,  or  cisterns  with- 
out being  covered  insect-tight. 

Through  systematic  application  of 
these  methods,  Panama,  Cuba,  New  Orleans,  and  many  cities 
in  the  north  have  effectually  rid  themselves  of  mosquitoes. 
The  results  of  these  campaigns  prove  that  the  extermination 
of  the  mosquito  from  any  locality  is  no  longer  a  matter  of 
doubt  or  experiment.   Through  drainage  of  salt  marshes  whole 


Fig.  70.    Jam  bottle  and 

tumbler  arranged  so  as 

to  secure  eggs  of  a  single 

mosquito 


Fig.  71.    Connecticut  salt  marsh  before  draining 


Fig.  72.    Connecticut  salt  marsh  after  draining 
Photographs  by  W.  E.  Britton 


134 


INSECT  TYPE  PROBLEMS  135 

states  are  being  freed  from  migrating  mosquitoes  (Figs.  71, 
72).  Incidentally,  the  yield  of  marsh  hay  is  increased  on  these 
swamps,  so  that  it  more  than  pays  for  the  cost  of  drainage. 

Locating  Anopheles  and  Aedes  mosquitoes  in  a  neighbor- 
hood does  not  necessarily  mean  that  malaria  and  yellow  fever 
are  present.  These  mosquitoes  are  not  dangerous  to  health 
unless  they  have  first  bitten  people  sick  with  malaria  or 
yellow  fever. 

Planning  a  campaign.  You  may  carry  on  a  campaign 
against  the  mosquito  in  a  single  neighborhood  or  you  may 
conduct  it  as  a  city-wide  movement.  In  either  case  offer 
your  services  as  a  class  to  the  board  of  health.  If  malaria 
is  present,  your  map  showing  location  of  breeding  places 
of  Anopheles  might  be  offered  to  the  board  and  cooperation 
secured  in  wiping  out  the  disease.  Arrangements  should  be 
made  to  have  a  doctor  examine,  free  of  charge,  any  one  who 
has  even  a  slight  suspicion  that  he  has  malaria.  Quinine  is  a 
cure  for  this  disease,  and  every  malarial  patient  should  make 
use  of  this  remedy  (under  the  duection  of  a  physician)  and 
should  be  screened  from  mosquitoes  to  prevent  them  from 
becoming  infected. 

Allow  the  newspapers  to  publish  the  results  of  your  work, 
together  with  the  accounts  of  mosquitoes  and  the  methods 
of  exterminating  them.  It  is  of  the  utmost  importance  that 
every  one  enter  the  campaign  with  enthusiasm,  as  a  few  care- 
less and  ignorant,  people  may  contmue  to  breed  mosquitoes 
by  thousands  in  all  sorts  of  rubbish  that  can  hold  a  small 
amount  of  water. 


CHAPTER   XII 

mSECT  TYPE  PROBLEMS:  CABBAGE  BUTTERFLY 
(PONTIA   RAPjE) 

Pontia  rap(£.  This  white  butterfly  commonly  seen  flitting 
over  garden  and  roadside,  has  long  been  a  serious  pest.  It 
gains  its  familiar  name  —  cabbage  butterfly  —  from  ravages  of 
the  larva  upon  the  Crucifer  family,  especially  the  cabbage.  In 
the  northernmost  portion  of  North  America  it  is  two-brooded, 
in  the  latitude  of  New  England  three-brooded,  and  farther 
south  many-brooded.  A  butterfly  has  been  known  to  contain 
over  500  eggs,  and  the  progeny  of  a  pair  of  cabbage  butterflies 
in  a  season  in  the  latitude  of  Boston  is  estimated  as  31,375,500. 

The  cabbage  butterfly  was  accidentally  introduced  into 
America  from  Europe  in  1860,  and  twenty -five  years  later  it 
had  spread  over  nearly  the  length  and  breadth  of  the  land. 
This  rapid  invasion  was  due  to  the  fact  that  its  natural  enemy, 
the  ichneumon  fly  (^Apanteles  glomeratus)^  was  not  present  to 
hold  it  in  check.  This  insect,  however,  was  introduced  in 
1883  and  is  increasing  rapidly.  The  cabbage  butterfly  may  be 
collected  in  its  different  stages  and  the  specimens  kept  in 
breeding  cages  (Fig.  73)  for  study.  Larvae,  thrive  well  in  the 
laboratory  if  they  are  supplied  with  fresh  cabbage  leaves. 

Eggs  and  larvae.  The  small  yellow  eggs  are  deposited  singly 
on  the  undersurface  of  cabbage  leaves.  Keep  in  water  in  the 
laboratory  leaves  upon  which  eggs  have  been  deposited,  noting 
how  long  it  takes  the  eggs  to  hatch.  Measure  the  young  larva 
and  note  the  time  it  requires  to  double  in  length.  Does  its 
color  match  that  of  the  leaf  upon  which  it  is  feeding  ?  What 
is  the  advantage  of  this  ? 

136 


CABBAGE  BUTTEKFLY 


137 


Place  some  larvte  in  a  cyanide  bottle.  Study  and  draw 
a  specimen.  Can  you  find  the  six  single  eyes  (ocelli)  on 
the  side  of  the  head  ?  Note  the  small  feelers  (antennce)^  and 
the  strong  teeth  (mandibles).  How  many  pairs  of  jointed 
legs  lias  the  thorax  ?  How  many  unsegmented  legs  (prolegs) 
on  the  abdomen  ?  Note  the  number  of  segments  on  the 
abdomen,  and  locate,  if  possible,  all  the   spiracles. 

Pupa.  After  a  larva  is 
full-grown  it  ceases  to  eat 
and  becomes  restless,  leav- 
ing the  cabbage  and  crawl- 
ing about.  When  these 
symptoms  are  seen,  keep 
a  larva  under  a  glass  for 
observation.  Note  that  it 
spins  a  mat  of  silk  into 
which  the  claws  of  the 
last  pair  of  prolegs  are 
fastened,  and  a  girdle  of 
silk  over  the  middle  of 
its  back.  After  it  is  thus 
securely  fastened  it  draws 
•its  head  down.  When  it 
has  remained  in  this  posi- 
tion for  some  time,  the 
skin  splits  over  the  head 


Female. 


Male. 


Fig.  73.  Insect  case  to  show  biology  of  cab- 
bage butterfly 


and  thorax,  and  we  find  a  chrysalis  ui  place  of  the  green  larva. 
Draw  the  pupa  as  it  is  fastened  by  its  girdle.  Search  for 
pup8D  and  make  a  list  of  places  where  they  are  found.  Save 
as  many  as  possible  in  order  to  see  the  butterflies  emerge. 

Adult  or  imago.  The  rapid  distribution  of  cabbage  butterflies 
is  due  to  their  flight  across  the  countiy  from  garden  to  garden, 
and  to  the  conveyance  of  the  chrysalis  on  carriages  and  trains. 
Follow  the  butterfly  for  fifteen  minutes  and  keep  a  record  of 


138 


CIVIC  BIOLOGY 


all  that  it  does.  It  sips  nectar  from  flowers,  and  does  much  to 
fertilize  them.  The  female  imago  is  distinguished  by  having 
two  black  spots  upon  its  fore  wing  while  the  male  has  only  one. 
From  your  specimens  in  the  laboratory  study  the  butterfly, 
notmg  its  parts.    Draw  from  the  side  and  from  above.    Make 

drawings  of  the  head  from  the 

1^ —  side,    one    with    the    proboscis 

I  curled  up,  and  another  with  it 

ra  extended.     (Place  a  little  thin 

sirup  near  the  head  and  watch 
the  butterfly  unroll  its  proboscis 
and  sip  it.)  Compare  the  struc- 
ture of  the  body  with  that  of 
the  pupa.  Mount,  according  to 
directions,  the  complete  life  his- 
tory of  the  butterfly  (Fig.  73). 
Control  of  the  pest.  Artificial 
means  of  control  are  (1)  Paris 
green,  sprinkled  over  the  leaves, 
killing  the  worms  but  not  injur- 
ing the  plant;  (2)  kerosene 
emulsion  as  a  spray ;  (3)  water, 
heated  to  130°  F.,  may  be  used 
without  injury  to  the  plant; 
(4)  systematic  "  netting "  of 
adults*  The  most  effective  meas- 
ure, however,  has  been  the  in- 
troduction of  its  natural  enemy, 
Apanteles  glomeratus. 
This  minute  wasp-like  insect  deposits  its  eggs  in  the  body 
of  the  cabbage  caterpillar  where  they  soon  hatch  and  feed  upon 
the  tissues  of  the  host.  They  grow  until  they  are  about  to 
pupate,  and  then  eat  their  way  out  and  spin  their  silken 
cocoons  on  or  near  the  bod}^  of  their  enfeebled  host.    The 


Fig.  74.    Convenient  arrangement 
for  studying  larvae 

.  Two  tumblers  with  card  between 


CABBAGE  BUTTERFLY 


139 


cabbage  larva  that  is  parasitized  by  the  ichneumon  fly  usually 
dies  before  it  transforms  into  a  chrysalis.  The  adult  ichneumon 
fly  emerges  from  its  cocoon  in  a  week  or  ten  days.    It  is  not 


Fig.  75.    Imported  parasite  of  the  cabbage  butterfly  — 
Apanteles  glomeratus 

Open  cocoon,  adult  insect,  and  mass  of  cocoons  near  parasitized  larva. 
Highly  magnified 

known  how  long  it  lives  or  how  many  generations  occur  in  a 
year.  The  fact  that  it  is  holding  the  butterfly  in  check  in  some 
localities  would  lead  to  the  belief  that  it  multiplies  more 
rapidly  than  its  host. 


140  CIVIC  BIOLOGY 

The  larva3  that  are  "infested  with  the  parasites  are  usually 
a  paler  green  and  are  not  so  easily  bent.  Examine  a  number 
of  larvae,  keeping  in  a  closed  vivarium  those  suspected  of  be- 
ing parasitized.  How  many  parasites  are  found  in  a  single 
larva  ?  The  parasitic  larvse  begm  to  spin  their  cocoons  as  soon 
as  they  emerge  from  their  host.  With  the  aid  of  a  lens  watch 
this  interesting  process  and  note  the  length  of  time  it  takes  to 
complete  the  cocoons. 

Apanteles  does  not  escape  without  its  enemies.  Two  small 
chalcis  flies  prey  upon  it,  but  thus  far  have  not  been  effective 
in  checking  its  ravages  upon  the  cabbage  worm. 


CHAPTER  XIII 
INSECT  TYPE  PROBLEMS:  ANTS 

No  other  group  of  animals  presents  such  a  maze  of  fascinating  problems 
to  the  biologist,  psychologist,  and  sociologist.  —  Wheeler,  "Ants,"  p.  11 

If  I  had  to  choose  the  form  in  which  I  would  prefer  to  live  again,  I  am 
not  sure  that  I  should  not  like  to  be  an  ant.  You  see  that  little  insect  lives 
under  the  conditions  of  perfect  political  organization.  Every  ant  is  obliged 
to  work,  to  lead  a  useful  life  ;  every  one  is  industrious.  There  is  perfect 
subordination  to  the  good  of  all,  discipline  and  order.  They  are  happy,  for 
they  work.  — Bismarck 

Economic  importance.  Over  a  thousand  species  of  ants  have 
been  described,  of  which  about  two  hundred  belong  to  North 
America.  As  a  group  they  are  generally  considered  distinctly 
beneficial  insects,  though  among  so  many  species  it  is  not 
strange  that  a  few  are  injurious.  Forel  counted  28  dead  in- 
sects per  minute  brought  in  by  the  foragers  of  a  large  colony, 
and  estimated  that  this  colony  collected  100,000  insects  per 
day.  In  China  live  ants  are  an  article  of  commerce  and  are 
regularly  used  to  control  injurious  insects  in  gardens  and 
orchards.  The  Department  of  Agriculture  has  recently  tried 
the  experiment  of  importing  a  Guatemalan  ant,  the  kelep,  in 
the  hope  of  discovering  an  effective  enemy  of  the  cotton-boll 
weevil.  Observations  of  ants  attacking  injurious  insects  should 
be  carefully  recorded  and  reported  to  the  class. 

Many  species  burrow  deep  into  the  earth,  opening  up  the 
soil  to  air  and  moisture  and  preparing  it  for  easy  penetration 
of  roots,  and  bring  quantities  of  fine  subsoil  to  the  surface. 
In  this  way  ants  supplement  the  work  of  earthworms  in  the 
forrpation  of  vegetable  mold. 

141 


142  .  CIVIC  BIOLOGY 

Three  species,  the  red  ant,  little  black  ant,  and  pavement 
ant,  are  common  household  pests  which  can  easily  be  looked 
up  in  state  or  national  bulletins  if  they  are  locally  important. ^ 
Serious  damage  is  sometimes  inflicted  by  the  corn-root  louse 
(^Aphis  maidi-radicis).  The  eggs  of  this  aphid  are  cared  for 
over  winter  by  the  common  brown  ant  QLasius  hrunneus).  They 
hatch  early  in  the  spring  and  the  ants  carry  the  young  aphids  to 
various  grasses  and  weeds  in  the  field,  and  later  transfer  them 
to  the  roots  of  the  corn.  Concerted  work  of  farmers  over  an 
infested  area  by  early  spring  plowing  and  repeated  disk  har- 
rowing, so  that  no  weeds  are  allowed  to  grow  before  the  corn 
is  planted,  effectually  controls  both  ants  and  aphids.  This 
topic  is  well  adapted  to  laboratory  demonstration  and  experi- 
ment in  infested  districts  and  where  education  is  needed  to 
secure  general  cooperation. 

The  chief  mterest,  however,  attachmg  to  a  study  of  ants 
is  their  seeming  intelligence  and  wonderfully  perfect  civic 
organization  of  the  colony. 

The  colony.  Ant  colonies  are  composed  of  queens,  males,  and 
workers.  Queen  ants  are  usually  larger,  are  wingless  when 
mature,  and  sometimes  live  fifteen  years ;  the  males  are  smaller, 
always  winged,  and  never  live  more  than  one  year.  The  workers 
may  be  distinguished  readily  from  the  queens  and  males  by  their 
small  size  and  lack  of  wings.  They  do  all  the  work  of  caring 
for  the  queen  and  her  young,  gathering  food,  building  and  de- 
fending the  nest,  caring  for  plant  lice  (aphids)^  and  waging  war. 

Before  mating,  the  queens  have  wings.  In  the  summer  and 
early  fall  clouds  of  young  queens  and  males  leave  the  differ- 
ent colonies,  flying  in  thousands.  The  flight  over,  the  queen 
is  either  adopted  by  an  old  colony  or  establishes  a  new  one. 
When  once  established,  she  removes  her  wings  and  never 
leaves  the  colony.  While  there  is  usually  but  one  queen  in  a 
colony,  there  may  be  as  many  as  thirty. 

1  Hodge,  Nature  Study  and  Life,  p.  86  ff. 


PLATE  111.    LIFE  HISTOKY  OF  THE  BKOWX-TAIL  MOTU 

1,  egg  cluster ;    2,  single  egg  (enlarged  five  diameters)  ;    3,  winter  nests 

(reduced  about  one  half)  ;  4,  caterpillar ;  6,  pupse,  male  at  right,  ventral 

view ;  female  at  left,  dorsal  view ;  6  and  7,  female  and  male  moths 


ANTS  143 

Food.  Ants  feed  upon  both  animal  and  vegetable  matter. 
Their  foraging  raids  extend  over  a  radius  of  forty  yards  from 
the  nest.  They  often  take  food  iirto  the  nest,  and  in  cold 
climates  they  hibernate  during  the  winter.  Much  of  the  food 
of  the  queen  and  larvae  is  eaten  by  the  workers  and  regurgi- 
tated from  the  crop  when  they  return  to  the  nest.  Ants  have 
a  preference  for  sweet  food,  such  as  juices  of  fruits,  sugar, 
honey,  and  honeydew.  Aphids  secrete  honeydew,  and  on  that 
account  are  cared  for  by  the  ants,  taken  into  the  ant  nests 
over  winter,  and  in  the  spring  carried  back  to  the  plants  upon 
which  they  feed.  But  the  aphids  are  among  the  insects  most 
injurious  to  vegetation,  and  their  protection  by  ants  may  be 
of  great  economic  importance  to  us.  Watch  the  problem  in 
your  own  locality. 

Special  senses.  The  organs  of  sight  and  hearing  are  very 
slightly  developed  in  the  ant,  but  the  sense  of  smell  is  espe- 
cially keen.  This  sense  is  situated  in  the  antennae.  The  ant 
travels  from  its  nest  and  finds  the  way  back  by  the  odor  of 
its  own  tracks.  If  a  portion  of  the  path  the  length  of  its  own 
body  is  disturbed,  the  ant  is  lost  and  wanders  about  until  it 
picks  up  the  trail  again,  but  a  path  left  dry  and  undisturbed 
can  be  followed  by  it  five  days  later.  Experiments  show  that 
its  own  nest  is  evidently  detected  at  quite  a  distance  by  odor, 
but  the  odor  of  other  ants  is  supposed  to  be  recognized  only  by 
touching  with  the  antennae.  Each  species  of  ant  has  a  distinct, 
characteristic  odor.  Different  colonies  also  of  the  same  species 
differ  slightly.  In  general,  the  odor  of  one  species  of  ants  is 
offensive  to  those  of  another  species,  and  causes  aversion  and 
hostility.    This  is  shown  by  well-defined  warfare  and  slavery. 

Slavery.  While  most  ants  will  capture  and  carry  away 
the  young  of  another  species  whenever  the  opportunity  is 
offered,  there  are  three  species  in  America  (^Formica  sangui- 
nea,  Polyergus  rvfescens,  and  Tomognathus  americanus)  that 
plunder  the  nest  of  their  enemy  and  rear  the  young  as  slaves. 


144  CIVIC  BIOLOGY 

The  slaves  undertake  the  work  of  the  new  nest  much  as  they 
woukl  that  of  their  own.  Can  you  find  ant  colonies  with  slaves  ? 
Warfare.  Many  comparisons  have  been  made  between  ants 
and  man  because  of  the  diversity  of  their  activities.  Ants  are 
said  to  indulge  in  games  and  athletic  sports  and  to  carry  on 
war.  The  following  observations  are  recorded  that  they  may 
incite  some  young  Lubbock  or  JMcCook  to  find  the  cause  and 
purpose  of  these  wars. 

On  the  morning  of  June  20, 1883, 1  observed  numbers  of  large  black 
ants  wandering  excitedly  over  a  back  piazza  of  my  house  in  Boxford,  Mass- 
achusetts. More  careful  observation  showed  a  dozen  of  their  dead  bodies 
scattered  around,  while  two  living  insects  were  struggling  in  a  desper- 
ate conflict.  In  some  places  dissevered  legs  and  antennae  were  thickly 
strewn,  while  in  retired  nooks  living  ants  were  resting,  either  exhausted 
or  skulking.  I  gathered  over  twenty  corpses  from  the  piazza  and  the 
ground.  Some  of  these  warriors,  having  mutually  inflicted  mortal 
wounds,  had  never  relaxed  their  iron  embrace,  but  lay  dead  in  pairs. 

The  conflict  was  not  yet  ended,  and  I  watched  one  of  these  Homeric 
encounters.  An  ant  had  his  antagonist's  feeler  in  his  jaws.  The  com- 
batant, thus  held,  twisted  and  turned  to  get  his  own  mandibles  upon 
feeler,  leg,  neck,  or  waist  of  his  antagonist.  He  was,  evidently,  much 
unnerved  by  the  other's  hold,  for  these  antennae  seem  as  sensitive  as  the 
eyeball,  and  he  was  dragged  about,  resisting  and  struggling  in  every 
way,  but  all  in  vain.  Finally,  the  antenna  came  off  near  the  base  and 
the  two  warriors  parted. 

Single  combats  like  this  probably  went  on  through  the  day,  and  a  few 
occurred  the  following  night,  for  in  the  morning  I  found  more  dead 
bodies.  One  wounded  soldier  died  in  my  custody,  and  many,  doubtless, 
in  cracks  and  nooks,  but  the  level  floor  seemed  to  be  the  main  battle- 
field. Altogether  T  collected  from  the  fight  about  seventy  complete 
bodies  or  dissevered  heads,  which  I  preserved  in  a  red  pill  box  —  the 
rather  gaudy  tumulus  of  this  "Waterloo  I 

In  the  same  place  on  the  morning  of  July  7,  following,  I  found  traces 
of  another  battle  which  was  not  yet  finished.  Again,  July  19,  there  had 
been  a  battle  during  the  night  on  the  bare  floor  of  a  chamber  at  the 
opposite  end  of  the  house  and  upstairs.  One  morning  in  August,  of  the 
same  year,  I  found  traces  of  a  similar  battle  in  the  cellarway  of  a  neigh- 
boring house.  —  AV.  P.  Alcott,  Bulletin,  Essex  Institute,  1897,  p.  65 


ANTS  145 

A  Study  of  Ants  in  the  Laboratory 

The  nest  (formicary).  Most  species  of  ants  readily  adapt 
themselves  to  an  artificial  nest.  After  the  first  few  weeks 
they  become  accustomed  to  their  surroundings,  and  may  live 
for  years  working  and  rearing  their  young,  much  as  they  do 
in  their  natural  environment. 

Kellogg  in  his  ''  American  Insects "  describes  several  of 
the  more  commonly  used  formicaries.  The  large-sized  insect- 
mounting  cases  serve  admirably  in  this  capacity.  The  case 
should  be  partitioned  off  into  two  or  three  rooms,  by  glueing 
strips  of  wood  that  reach  nearly  across.  On  the  top  of  the 
walls  of  the  case  glue  strips  of  Turkish  toweling,  so  that  air 
may  pass  to  the  rooms  after  the  upper  glass  is  in  place. 
Choose  two  pieces  of  heavy  glass  of  unequal  size  for  the  roof 
of  the  formicary,  so  that  one  piece  will  cover  two  rooms. 
Exclude  the  light  from  these  rooms  by  placing  blotting  paper 
over  the  glass,  and  keep  a  wet  sponge  (finest  texture)  in  each 
of  the  darkened  rooms.  All  food  should  be  kept  in  the  light 
room,  and  should  consist  of  small  pieces  of  sponge  cake, 
moistened  with  sirup  or  honey,  apple,  mashed  nuts,  dried 
fruit,  and  insects.  Keep  the  sponges  wet.  In  cool  weather 
the  food  need  not  be  clianged  oftener  than  once  in  two  weeks. 

How  to  obtain  an  ant  colony.  Dig  up  an  ants'  nest  and 
take  larvae,  pupse,  and  woi-kers.  If  you  cannot  find  the 
queen,  release  the  captives  and  try  other  nests  until  success- 
ful. Carry  the  queen  by  herself  in  an  envelope,  and  the 
young  and  workers  with  some  earth  in  a  cloth  or  paper  bag. 
Upon  reaching  the  laboratory,  empty  the  earth  and  ants  upon 
a  board  afloat  in  water;  pick  out  the  ants  and  young  from 
the  earth  and  place  them  with  the  queen  in  the  nest.^ 

1  An  easy  way  to  manage  tliis  is  to  scrape  a  hollow  in  the  center  of  the 
pile  of  earth,  put  the  queen  in  this,  and  cover  it  with  a  chip.  The  ants  will 
then  collect  all  the  eggs  and  larvae  into  a  pile,  and  they  may  be  lifted  into 
the  nest  with  a  spoon. 


146  CIVIC  BIOLOGY 

The  carpenter  ant  (^Oamponotus  pennsylvanicus)  is  one  of 
the  most  satisfactory  species  to  study.  The  colony  lives  in 
wood,  and  hibernating  queens  may  be  obtamed  under  the  bark 
of  stumps  or  logs  in  the  fall  or  during  a  winter  thaw. 

In  general  the  logs  and  stumps  in  which  they  are  found 
are  not  badly  decayed.  ]\Iost  frequently  queens  are  hiding 
beneath  bark  that  may  without  difficulty  be  removed  with  the 


Fig.  76.   Ants'  nest 

This  is  made  of  an  insect-mounting  strip,  5  by  7  inches,  \  inch  deep,  glued,  with  the 
two  partial  partitions,  to  the  bottom  glass.  The  top  glass  is  cut  so  that  one  piece 
covers  one,  and  the  other  two,  of  the  compartments.  A  braided  cotton  twine  is 
glued  along  the  top  of  the  frame  and  partitions  to  insure  ventilation.  The  sponge,  in 
the  middle  compartment,  is  kept  moist ;  and  the  living  chamber,  to  the  left,  is  kept 
dark  when  not  under  observation.    Designed  and  photographed  by  the  author 

fingers.  The  queen  is  curled  up  in  a  cleared  space  under  the 
bark  and  may  be  alone  or  accompanied  by  several  eggs,  larvae, 
pupae,  or  workers. 

Having  secured  a  queen  of  Camponotus  pemist/lvammis,  place 
her,  together  with  her  young,  in  a  nest  and  carefully  observe 
the  beginning  of  an  ant  colony.  Observations  should  continue 
for  the  remainder  of  the  year  and  careful  notes  made  to  reen- 
force  those  taken  upon  ants  in  the  field. 

Eggs.    The  queen  may  not  lay  for  a  month  or  more  after 


ANTS  147 

she  has  been  brought  into  the  laboratory.  Note  the  uitervals 
during  which  eggs  are  laid.  Describe  the  action  of  the  queen 
and  workers  m  regard  to  the  eggs  when  the  nest  is  disturbed. 
How  soon  do  ants  become  accustomed  to  the  careful  interfer- 
ence of  being  observed  ?  Fill  the  sponges  with  water,  one  day 
hot,  another  day  cold.  What  effect  upon  tlie  apparent  care  of 
the  eggs  has  a  difference  in  moisture,  temperature,  and  light  ? 

Larva.  The  time  taken  for  the  eggs  to  hatch  depends  upon 
the  warmth  and  humidity  of  the  atmosphere.  The  time  of  in- 
cubation is  about  twenty  days.  The  larvae  are  soft,  footless 
grubs,  the  smaller  end  being  the  head.  The  presence  of  hooked 
hairs  upon  the  bodies  of  the  larvce  explains  how  they  are  car- 
ried in  bundles.  Note  that  the  larvae  are  helpless.  They  are 
not  only  fed  by  the  queen  and  workers,  but  are  carried  about 
to  places  of  proper  temperature  and  humidity.  With  the  aid 
of  a  lens  observe  how  the  workers  and  queen  feed  the  larvse. 
The  queen  has  food  stored  m  her  body,  which  enables  her  to 
live  and  feed  her  first  brood  without  herself  taking  food.  This 
fact  probably  accounts  for  the  small  size  of  the  first  brood, 
which  is  composed  of  workers,  as  compared  with  subsequent 
broods.  The  queen  is  relieved  of  all  work  when  the  workers 
appear.  They  feed  her  and  the  larvse  and  assume  all  work 
of  the  colony. 

Note  that  the  larvae  are  of  different  ages,  and  that  they 
spin  cocoons  as  soon  as  they  become  full-grown.  Are  the  lar- 
vae and  pupae  kept  together?  Ants  have  no  regular  places 
for  their  young ;  even  in  the  natural  nest  they  are  carried  to 
places  which  offer  suitable  conditions.  The  pupa  stage  like 
the  larval  lasts  about  twenty  days  when  the  temperature  is 
about  80°.  Observe  that  the  cocoon  turns  yellowish  before 
the  young  ant  (callow)  appears.  How  long  before  the  callows 
assume  the  duties  of  adult  workers  ? 


CHAPTER  XIV 
SPECIAL  PROBLEMS  OF  INSECT  CONTROL 

The  life  histories  of  insects  lie  at  the  foundation  of  the  whole  subject  of 
economic  entomology,  and  constitute,  in  fact,  the  principal  part  of  the  sci- 
ence, for  until  these  are  clearly  and  completely  made  out  for  any  injurious 
species,  we  cannot  possibly  tell  when,  where,  or  how  to  strike  it  at  its 
weakest  point,  —  S.  A.  Fokbes 

Control  of  insects  by  a  community  or  nation  must  depend 
upon  each  citizen  knowing  the  important  species  and  actually 
doing  his  part.  Insects  are  so  small,  tough,  and  hard  to  kill, 
and,  above  all,  possess  such  powers  of  rapid  dissemination  and 
increase,  that  the  problems  of  insect  control  are  probably  the 
most  difficult  hi  the  whole  field  of  livhig  forces.  However,  in 
the  life  history  of  a  species  from  the  egg,  through  the  actively 
feeding  larval  stage,  in  the  quiescent  pupal  condition,  or  in 
the  adult,  egg-laying  period,  it  is  generally  possible  to  discover 
some  tveakest  point  at  which  it  may  be  successfully  attacked. 
To  work  out  these  life  histories,  discover  these  vulnerable 
points  of  attack,  and  devise  best  ways  and  means  is  the 
function  of  our  scientific  experts  ;  but,  in  order  that  these 
discoveries  accomplish  their  purpose,  the  people  must  learn 
and  use  the  results. 

Organization  for  both  research  and  information  is  so  perfect 
that  if  any  one  wishes  to  know  about  an  insect  he  has  only  to 
inquire  of  his  State  Experiment  Station  or  of  the  United 
States  Department  of  Agriculture  at  Washington.  If  the 
answer  to  his  question  is  known,  it  will  be  sent  to  him  prac- 
tically by  return  mail.  If  not,  a  special  research  may  be 
ordered  to  solve  the  problem. 

148 


SPECIAL  PROBLEMS  OF  INSECT  CONTROL      149 

As  a  nation  we  are  paying  about  $25,000,000  annually  for 
the  discovery  and  dissemination  of  just  this  sort  of  informa- 
tion. If  we  are  not  "  getting  our  money's  worth,"  it  is  our 
own  fault.  One  truth  with  regard  to  an  insect  which  causes 
disease  or  levies  a  tax  of  often  hundreds  of  millions  of  dollars 
on  some  staple  crop  may  be  worth  the  entire  annual  cost  of 
tlie  scientific  departments  of  the  government,  as  soon  as  the 
knowledge  is  put  to  use. 

With  hundreds  of  experts  working  at  these  problems,  knowl- 
edge is  growing  so  fast  that  statements  are  likely  to  be  super- 
seded before  the  ink  of  a  book  is  dry.  In  order  to  keep  up  to 
date,  every  biological  laboratory  should  have  available  for  all 
students  two  important  publications,  the  Monthly  List  of  Piih- 
lieations  and  the  Experhneiit  Station  Record.,  both  issued  by 
the  United  States  Department  of  Agriculture.  These  will 
keep  the  student  informed  of  every  advance  in  our  knowledge 
of  insects,  as  well  as  of  a  great  many  other  matters  of  interest. 

Make  a  list  of  the  most  important  insects  of  the  neighbor- 
hood, or  those  about  which  you  wish  to  learn,  and  follow  them 
through  the  indexes  of  the  Expenment  Station  Record.  Send 
to  your  State  Experiment  Station  or  to  Washington  for  the 
bulletins  you  need,  and,  after  studying  them  and  collecting 
and  observing  your  specimens  in  the  field,  mounting  them  so 
that  they  will  tell  as  complete  a  story  as  possible,  be  ready  to 
report  your  results  to  the  class. 

Working  independently  and  without  consultation,  let  each 
member  of  the  class  prepare  a  list  of  the  insects  which  lie  thinks 
every  member  of  the  community  ought  to  know  in  order  to 
prevent  annoyance,  spread  of  disease,  damage  to  household 
goods,  stock  or  crops.  This  should  be  done  after  working 
through  the  laboratory  types  given  in  Chapters  X-XIII,  read- 
ing bulletins  and  books  assigned,  and  studying  the  lists  given 
below.  After  comparing  and  discussing  individual  lists,  pre- 
pare a  class  list  which  shall  include  the  most  important  local 


150  CIVIC  BIOLOGY 

problems,  and  one  which  the  class  can  reasonably  cover  dur- 
ing the  year,  and  then  write  the  names  on  slips  and  let  each 
draw  a  certain  number,  or  distribute  by  individual  preference, 
as  the  class  may  elect.  As  these  studies  progress  they  should 
be  reported  and  freely  discussed.  Thus  the  biology  class  may 
be  the  organizing  center  for  a  better  understanding  of  local 
insect  problems,  and  enlist  cooperation  of  homes  and  of  boys 
and  girls  in  the  lower  grades  for  more  effective  effort  and 
better  local  control. 

The  problem  of  insect  classification.  It  is  recognized  that  for 
an  elementary  and  practical  course  the  complete  classification 
of  insects  is  too  difficult  and  would  take  too  much  time.  The 
vast  number  of  species,  more  than  three  hundred  thousand,  are 
commonly  grouped  into  nineteen  orders,  and  any  student  who  is 
specially  interested  can  find  the  subject  fully  treated  in  manuals. 
For  all  elementary  purposes  it  will  be  sufficient  to  learn  the 
names  and  characters  of  the  seven  more  important  orders.  Every 
one  ought  to  know  what  we  mean  by  a  "fly,"  a  "bee,"  a  "bug,". 
a  "  moth  or  butterfly,"  a  "locust,"  a  "  beetle,"  a  "  lacewing." 

Since  classification  consists  in  gathermg  into  groups  forms 
with  similar  structures  and  parts,  we  need  to  learn  somethnig 
of  the  way  an  insect  is  constructed.  To  begm,  take  any  large 
insect,  a  beetle  or  grasshopper,  and  work  out  all  the  apparent 
subdivisions  of  the  body.  Note  the  three  mam  subdivisions  — 
head,  thorax,  and  abdomen  —  and  locate  the  breathing  pores 
(spiracles)  as  indicated  in  Fig.  77.  Insects,  spiders,  and  myria- 
pods,  instead  of  having  one  pair  of  nostrils,  a  wmdpipe,  and 
lungs  to  which  the  blood  is  brought  to  be  oxygenated,  circu- 
late the  air  directty  to  the  tissues  by  means  of  fine,  elastic, 
branching  tubes.  These  are  known  as  tracheae,  and  these  ani- 
mals are  known,  since  this  is  a  character  of  great  significance, 
as  tracheates.  Contact  insecticides  —  oil  films  on  water  for  mos- 
quitoes, oil-emulsion  or  soapy  sprays  —  depend  upon  clogging 
these  fine  breathmg  pores  and  thus  smothering  the  insect. 


SPECIAL  PEOBLEMS  OF  INSECT  CONTROL      151 


Water  will  not  do  this,  because  the  openings  are  protected 
against  its  entrance  by  oily  secretions.  Compare  the  effect 
of  dipping  an  insect  into  water  and  into  kerosene. 

Next,  beginning  at  the  head,  study  all  organs  and  mov- 
able parts  (appendages)  :  the  eyes,  feelers  (antennse,  replacing 

Head       Prothorax      Mesothorax     Metathorax      Abdomen 

Compmind  Ey^  \  /         , '  / 

Simple  Eye/ 


Fore  Wing 


Hind  Wing 


Labium 
Mouth-Parts 


Ovipositor 


Fig.  77.   External  anatomy  of  the  grasshopper 


ears  and  nose  as  sense  organs,  at  least  partly),  mouth  parts 
(very  complicated,  consisting  typically  of  an  upper  and  lower 
lip  (labrum  and  labium)  and  two  pairs  of  jaws  (mandibles 
and  maxillse),  which  move  sidewise  instead  of  up  and  down). 
Watch  a  caterpillar  or  grasshopper  eat  a  leaf  and  see  if  you 
can  discover  why  the  jaws  move  sidewise.  A  study  of  mouth 
parts  is  again  important  with  reference  to  methods  of  destroy- 
ing insects.  Those  that  bite  and  chew  can  be  killed  by  spraying 


152  CIVIC  BIOLOGY 

poisons  upon  their  food  plants  or  by  mixing  poisons  with  foods 
which  attract  them.  Those  whose  mouth  parts  have  been 
modified  into  an  apparatus  for  piercing  and  sucking  can  be 
reached  only  by  insecticides  which  kill  by  contact. 

The  thorax  is  divided  by  rather  conspicuous  sutures  into 
three  parts  named  prothorax,  mesothorax,  and  metathorax. 
Each  carries  a  pair  of  legs ;  that  is,  all  insects  have  three  pairs 
of  legs.  Wings  may  be  present  or  absent.  If  two  pairs,  they 
are  attached  to  the  meso-  and  meta-thorax,  and  a  single  pair 
is  usually  attached  to  the  meso-thorax.  The  insect  wing  is  the 
most  perfect  flying  mechanism  in  existence,  and  until  man  can 
match  its  structure  for  lightness  and  strength,  he  can  hardly 
hope  to  solve  completely  the  problem  of  flight. 

Note  that  insect  wings  vary  in  texture  from  the  hard,  shell- 
like structures,  as  in  the  fore  wings  of  beetles  and  the  leathery 
or  parchment-like  wings  of  grasshoppers  and  many  bugs,  to 
the  transparent  membranous  wings  of  bees  and  flies. 

The  abdomen  is  made  up  of  a  series  of  similar  rings  termi- 
nated by  various  organs  concerned  with  reproduction,  ovipos- 
itors, etc.,  sometimes  modified  into  sharp  stings. 

The  life  histor}^  of  an  insect  also  gives  characters  for  classi- 
fication. With  many  insects  the  egg  hatches  into  a  worm-like 
maggot,  grub,  or  caterpillar  wholly  unlike  the  parent,  and 
later  passes  through  a  quiet  stage  (pupa  or  chrysalis)  before 
becoming  like  the  parent.  In  these  cases  the  insect  is  said 
to  show  a  complete  metamorphosis  (ineta^  "  over " ;  morphe^ 
''  form"  —  "  change  of  form ").  Name  insects  that  you  know, 
of  which  this  is  true. 

In  other  insects  the  egg  hatches  into  something  like  the 
parent.  To  study  this  point,  watch  a  nest  of  grasshopper  or 
squash-bug  eggs  hatch.  These  insects  are  said  to  have  an 
incomplete  metamorphosis.  In  the  case  of  a  few  insects  — 
the  San  Jose  scale,  aphides,  and  some  of  the  flies  —  the  eggs 
hatch  within  the  body  and  the  young  are  born  alive. 


SPECIAL  PROBLEMS  OF  INSECT  CONTROL   153 

Of  the  nineteen  orders  the  seven  most  unportant  are : 

L  Diptera  (di-,  "two*';  pteroUy  "wing").  Two  membranous  wings, 
moiitli  parts  for  piercing  and  sucking  or  for  lapping ;  metamor- 
phosis complete,  larvie  various  in  form  and  habit  but  always  foot- 
less; maggots,  wrigglers,  etc.  Examples:  flies,  mosquitoes,  gnats ; 
40,000  known  species ;  estimated  number,  350,000  (Howard). 
IL  Coleoptera  (koleos,  "sheath";  pteron,  "wing").  Four  wings,  the 
front  pair  horny  cases  which  cover  the  membranous  hind  wings ; 
mouth  parts  for  biting ;  metamorphosis  complete,  the  larva  a 
grub,  with  usually  six  legs.  Examples :  beetles,  potato  beetle, 
June  beetle,  lady  beetle ;  100,000  known  species  (Galloway). 

III.  Hemiptera(hemi-,^^ half  ^^',  />^eron,  "wing").    Fore  wings  membra- 

nous, parchment-like  or  with  horny  bases  and  membranous  tips ; 
hind  wings  membranous  ;  many  wingless  forms  ;  metamorphosis 
incomplete,  the  young  resembling  the  adults,  but  wingless  — 
the  true  "  bugs."  Examples  :  plant  lice,  scale  insects,  cicadas,  lice, 
water  bugs;  20,000  known  species;  probably  80,000  in  all 
(Howard). 

IV.  Orthoptera  (orthos,  "straight";  pteron,  "wing").  Fore  wings  parch- 

ment-like, net-veined,  hind  wings  almost  always  membranous ; 
mouth  parts  for  ]>iting ;  metamorphosis  incomplete,  the  young 
resembling  the  adult,  but  wingless.     Examples  :  grasshoppers, 
crickets,    cockroaches,   walking    sticks ;    estimated    more    than 
10,000  species. 
V.  Lepidoptera  (lepis,  "scale";   pteron,  "wing").     Wings  and  body 
scale-clad  ;  mouth  parts  modified  into  a  coiling,  sucking  tube,  or 
absent ;  metamorphosis  complete,  larva  a  cateri)illar.   Examples  : 
butterflies  and  moths;  25,000  known  s}»ecies  ((Jalloway). 
Yl.  Hymenoptera   (hymen,    "membrane";    pteron,     "wing").     Wings 
four,  membranous,   a    few   wingless    forms ;    mouth  parts   for 
biting  and  lapping ;    metamorphosis  complete,  larva  maggot- 
•  like.   Examples  :  bees,  ants,  wasps,  sawflies,  ichneumons ;  about 
80,000  known  species ;  estimated  number,  300,000  (Howard). 
VII.  Neuroptera  (neuron,  "sinew"  ;  pteron,  "wing").  Wings  four,  mem- 
branous, usually  net-veined ;  mouth  parts  for  biting ;   metamor- 
phosis  incomplete   or   complete ;    larva   usually   unlike   adult, 
sometimes  aquatic.    Examples  :  dragon  flies,  lacewings,  etc.^ 

^  This  group  is  now  subdivided  into  eight  orders,  among  them  the  caddis 
flies  {Trichoptera)^  dragon  flies  (Odonata),  and  white  ants  (Isoptera). 


154  CIVIC  BIOLOGY 

Most  insects  in  the  following  lists  belong  to  the  above 
orders.  Each  represents  a  problem  of  interest  to  the  com- 
munity and  home,  and  the  time  will  come  when  each  citizen 
must  realize  that  he  has  no  moral  right  to  breed  pests  which 
cause  annoyance  and  damage  to  his  neighbors.  In  reading 
the  lists  review  what  you  have  learned  of  each  in  previous 
years,  especially  running  over  the  life  history. 

It  is  convenient  also  to  classify  insects  according  to  their 
point  of  attack  or  their  food  plants ;  as,  insects  of  the  house- 
hold, garden,  field,  forest ;  insects  of  the  apple,  grape,  peach, 
etc.  Many  books  for  practical  horticulturists  and  the  agricul- 
tural bulletins  treat  them  this  way. 

Insects  of  the  Household 

Flies  :  House  fly,  typhoid  fly,  or  filth  fly  —  Musca  domestica ;  small 
house  fly — Homalomyia  caniculaina ',  stable  fly  —  Stomoxys  calciirans ; 
cluster  fly  —  Pollenia  rudis ;  bluebottle  fly  or  blowfly  —  Calliphora  ery- 
throcepliala  \  green-bottle  fly  —  Lucilia  ccesar-,  fruit  fly  —  DrosopMla  am- 
pelophilia;  cheese  or  ham  skij)per  —  Piophila  casei. 

Mosquitoes  :  Common  domestic  species,  in  rain  barrels  and  stag- 
nant pools  everywhere  —  Culex  pipiens ;  malarial  mosquitoes  —  A  nopheles 
macuUpennis,  punctipennis,  and  crucians ;  and  the  yellow-fever  mosquito, 
throughout  the  South  and  wherever  it  is  found  breeding — Aedes  calopus. 

Clothes  Moths:  Case-making  clothes  moth — Tinea  pellionella; 
Southern  clothes  moth —  Tineola  bisselliella;  tapestry  moth —  Trichophaga 
tapetzella;  carpet  beetle  —  Anthreniis  scrophularioe ;  black  carpet  beetle 
—  Attagenus  piceus. 

House  Crickets  —  Gryllus  domesticus  and  G.  assimilis. 

Roaches:  American  cockroach  —  Periplaneta  americana;  oriental 
cockroach  —  Periplaneta  orientalis ;  German  roach,  Croton  bug  —  Ectohia 
germanica. 

Bedbug  :  Common  bedbug — Acanthia  lectularia  ;  blood-sucking  cone- 
nose  —  Conorhinus  sanguisuga  ;  kissing  bug  —  Opsiccetus  personatus 

Lice:  Head  louse  —  Pediculus  capitis;  body  louse  —  Pediculus 
vestimenti. 

Fleas:  Human  flea  —  Pulex  irritans-^  cat  and  dog  flea — Ctenoceph- 
alus  canis ;  rat  fleas  —  Ceratophillus  fasciatus  and  Pulex  cheopis ;  chigoe, 


SPECIAL  PROBLEMS  OF  INSECT  CONTROL      155 

burrowing  flea  (chiefly  tropical)  —  Sarcopsylla  penetrans ;  hen  flea  (bur- 
rows into  the  eyelids  of  fowls),  Southern  states  —  Xestopsylla  gallinacea. 

This  group  was  formerly  classed  with  the  diptera  but  is 
now  usually  given  as  an  order  by  itseK,  the  Siphonaptera 
(^siphon,  ''  a  sucking  tube  " ;  a,  "  without" ;  pteron,  ''  wing"  — 
"  wingless  bloodsuckers"). 

White  Ants  :  Termites  —  Termes  Jlavipes.  These  are  not  ants,  but 
belong  to  another  order,  the  Isoptera  (isos,  "equal";  ptei^on,  "wing"). 
Destructive  to  wood  of  buildings  and  furniture  and  even  to  living  trees. 

House  Ants  :  Red  ant  —  Monomorium  pharaonis ;  little  black  ant  — 
Monomorium  minutum ;  pavement  ant  —  Tetramorium  caespitum. 

Beetles  :  Larder  beetle  —  Dermestes  lardarius ;  drug-store  beetle  — 
silrodrepa  panicea;  meal  worms — Tenehrio  molitor  and  T.  obscurus; 
Indian-meal  moth  —  Plodia  interpunctella. 

The  above  are  only  a  few  of  the  more  important  household 
insect  pests.  Many  others  may  be  found  by  searching  the 
house,  and  can  be  identified,  if  they  present  interesting  local 
problems,  by  reference  to  the  books  mentioned  at  the  end  of 
this  chapter.  The  fact  that  no  headway  is  made  in  the  fight 
with  these  enemies  is  due  chiefly  to  lack  of  organized  coopera- 
tion. One  family  exterminates  them  and  is  reinfested  from  a 
neighbor  who  does  the  work  at  some  other  time. 

Insects  Injurious  to  Vegetation 

Orchard  Pests :  Codling  moth  —  Carpocapsa  pomonella;  tent  cater- 
pillars (apple-tree)  —  Clmocampa  americana ;  fall  webworm — Hypfiantria 
cunea]  cankerworms  (spring  —  Paleacrita  vernatci]  fall  —  Anisopteryx 
pometarid)  ;  yellow  woolly  bear  —  Spilosoma  virginica  ;  curculio  beetles, 
weevils  (apple — Anthonomus  quadrigibbus ;  plum — Conotrachelus  nenu- 
phar; quince — Conotrachelus  cratcegi;  grape — Craponius  incequalis; 
borer  beetles  ;  round-headed  apple-tree  —  Saperda  Candida  ;  flat-headed 
apple-tree —  Chrysobothris  femorata  (also  attacks  the  plum)  ;  pear-blight 
beetle — Xyleborus  pyri ;  pear-tree  borer  —  ^geria  pyri ;  cherry-tree  borer 
— Dlcerca  divaricata;  peach-tree  borer — Sanninoidea  exitiosa;  apple-twig 
borer — Amphicerus  bicaudatus);  sphinx  moths  ("humming-bird"  moth) 
(plum  —  Sphinx  drupiferarum;  green  grapevine —  Ampelophaga  myron); 


156  CIVIC  BIOLOdY 

scale  insects  (oyster-shell  scale  —  Mi/tilaspis  pomorum  ;  scurfy  scale  — 
Chionaspis  furfurus;  San  Jos6  scale,  Chinese  pernicious  scale  —  Aspid't- 
otus  perniciosus,  the  worst  fruit-tree  pest  on  the  American  continent; 
cottony  cushion  scale  —  Icerya  purchasi) ;  apple-tree  enemies  (yellow- 
necked  apple-tree  caterpillar  —  Datana  ministra ;  red-humped  apple-tree 
caterpillar  —  (Edemasia  conclnna ;  apple  sphinx,  or  hawk  moth  —  Sphinx 
gordius ;  apple  maggot, "  railroad  worm  " — Rhagoletis  pomonella^ ;  enemies 
of  small  fruits  (strawberry  crown  borer,  weevil  —  Tyloderma  fragrarkv. ; 
strawberry  root  borer  —  Anar.sia  lineatellci',  currant  borer,  American  — 
Psenocerus  aupernotatus  ;  currant  borer,  imported  —  u'Egerla  tipuliformis  ; 
grapevine  root  beetle  — Pr tonus  laticollis ;  grape-berry  moth — Polt/chrosis 
hotrana ;  grape,  gartered  plume  moth  —  Oxyptilus  periscelidactylus ;  rose 
chafer  —  Macrodaetylus  suhsptnosuft);  plant  lice  (aphids,  grape  —  Phyl- 
loxera  vastatrix;  woolly  apple  louse  —  Schizoneura  lanigera:  cherry  louse 

—  Myzus  cerasiy 

Vegetable,  Grain,  and  Cotton  Pests  :  Colorado  potato  beetle  — 
Doryphora  10-Uneata  ;  striped  cucumber  beetle  —  Diabrotica  vittata  ;  as- 
paragus beetle  —  Crioceru  aaparagi ;  June  beetle  (May  bug  in  the  South) 

—  Lachnoste?'na  fusca  and  others;  flea  beetles  —  Halticinl',  blister  or  oil 
beetles  —  Meloidcc,  cutworms  —  Noctuldoi  (larvfe  of  a  number  of  owlet 
moths  or  noctuids) ;  sphinx  moths  (tobacco.  South  —  PJdegethontius  sexta: 
tomato  —  Phlegethontius  quinqueniacidata)  ;  cabbage  worm,  imported  — 
Pontia  rapcv  ;  cabbage  looper  —  A  utographer  hrasslccc ;  cabbage  and  rad- 
ish maggot  —  Pegomyia  h'assicce  ;  onion  maggot  —  Phorhia  ceparum ; 
cotton  worm  —  Aletia  argillacea;  boll  worm  (corn-ear  and  tomato  worm 
of  the  North) — Heliothis  armigera\  army  worm  —  Leucania  unipuncta\ 
Hessian  fly  —  Meri^ius  destructor-^  corn-root  aphis  —  Aphis  maidi-radicis : 
grain  aphis  or  " green  bug  "  —  Toxoptera  gramineum ;  chinch  bug  —  Blissus 
leucopterus ;  squash  bug  —  A  nasa  tristis ;  grasshopi:)ers  (Rocky  Mountain 
locust) — Melanoplus  spretus;  red-legged  locust  —  Melanoplus  femur- 
ruhrum 

Forest  and  Shade-Tree  Enemies:  Gypsy  moth — Ocneria  dispar 
(one  of  our  most  diflicult  problems)  ;  brown-tail  moth  —  Euproctischrys- 
orrhea  (a  national  problem) ;  elm-leaf  beetle  —  Gahrucella  luteola ;  white- 
marked  tussock  moth —  Notolophns  leucostigma]  cottony  maple  scale  — 
Pulvinaria  innumerahilis. 

Most  of  the  Hymenoptera  are  highly  beneficial  insects,  but 
among  them  are  a  few  so  injurious  and  troublesome  that 
every  member  of  a  community  ought  to  know  them.    These 


SPECIAL  PROBLEMS  OF  INSECT  CONTROL     157 

are  leaf-eating  sawflies,  aiid  many  others  of  less  importance 
are  borers  and  gall  insects. 

Currant  worm  or  slug  —  Nematus  ventricosus ;  pear  slug  —  Eriocampa 
cerasi',  rose  slug  —  Monostetjia  rosfe. 

Insects  attacking  Animals  :  Botfly  (ox  warble)  —  llypoderma 
lineata ;  sheep  botfly  —  (Estrus  ovis  •  liorse  botfly  —  Gastrophilus  equi : 
horn  fly  —  Hoematohia  serrata ;  screw-worm  fly  —  Compsomyia  macellaria. 

Beneficial  insects.  As  it  is  said  to  ''  take  a  thief  to  catch  a 
thief,"  so  it  often  takes  an  insect  to  catch  an  insect.  From  the 
usual  study  of  injurious  forms  the  impression  is  likely  to  be 
given  that  almost  all  insects  are  injurious.  Yet  even  species 
which  cause  considerable  damage  may  perform  good  service  in 
cross-pollination  of  plants.  The  honeybee,  our  most  useful 
species  for  this  purpose,  has  the  distinct  advantage  of  winter- 
ing a  large  force  of  workers  ready  to  cover  the  fruit  bloom 
early  in  the  spring,  before  our  native,  solitary  bees  have  begun 
to  breed  in  numbers. 

The  problem  of  the  honeybee  and  fertilization  of  fruit  trees 
about  the  home  or  in  the  neighborhood  is  one  which  may  well 
repay  study.  The  question  is.  Are  there  bees  enough  to  do 
the  work  ?  The  stone  fruits  are  said  to  depend  entirely  on 
insect  cross-pollination  in  setting  fruit,  and  if  the  cherry,  plum, 
and  peach  trees  are  not  humming  at  some  time  during  the 
bloom,  there  will  be  little  or  no  fruit.  Apples  of  some  varie- 
ties and  most  pears  are  greatly  improved  in  quality  when 
cross-pollinated. 

For  at  least  one  hour  on  a  bright,  warm  day  while  the  trees 
are  in  bloom,  with  watch  in  hand,  time  and  count  the  number  of 
blossoms  visited  by  bees  per  minute.  Do  this  for  all  the  differ- 
ent kinds  of  fruit  accessible.  How  many  men  would  it  take 
to  do  the  work  of  one  swarm  of  bees  of  fifty  thousand  workers? 

Are  there  enough  bees  to  pollinate  the  flowers  and  gather 
the  nectar  in  the  neighborhood  ? 

Can  you  find  any  honeybees  working  on  red  clover  ? 


158  CIVIC  BIOLOGY 

Test  the  practical  value  of  insect  cross-pollination  by  cover- 
ing a  twig  of  cherry,  plum,  or  peach  with  wire  gauze  or  mos- 
quito netting  during  bloom.  Compare  the  fruit  of  this  twig 
with  a  similar  one  on  the  same  tree  which  was  not  covered. 

Is  there  any  evidence  that  orchards  near  apiaries  bear  better 
than  others  ? 

What  can  you  learn  of  the  comparative  merits  of  different 
races  of  bees  in  your  locality  ? 

National  problems.  In  the  above  list  three  insects  merit 
special  emphasis  as  presenting  civic  problems  of  national  im- 
portance. All  are  species  of  almost  unthinkable  destructive 
power  imported  from  the  Eurasian  continent,  and  until  re- 
cently, at  least,  without  their  natural  enemies. 

The  San  Jose  scale  was  imported  into  the  San  Jose  valley, 
California,  in  1868,  and  has  since  spread  over  almost  the  entire 
United  States.  During  this  time  it  has  probably  killed  more 
fruit  trees  than  all  other  insect  pests  combined,  and  is  now  the 
most  serious  menace  to  the  home  fruit  garden.  Minute  as  is 
the  insect,  one  pair  may  produce 'in  a  season  3,216,080,400. 
This  at  once  shows  how  little  chance  a  tree  can  have  and  how 
futile  any  treatment  is  which  leaves  even  a  few  pairs  alive. 
After  ten  years  of  experimenting  with  the  various  spraying 
mixtures  recommended,  the  writer  is  obliged  to  state  as  his 
opinion  that  nothing  has  yet  been  discovered  which  will  ex- 
terminate the  San  Jose  scale  from  a  tree.  Hence  it  is  of  the 
utmost  importance  for  the  class  to  follow  all  announcements  of 
discoveries  as  to  effective  methods  of  dealing  with  this  insect. 

Make  a  thorough  examination  of  your  home  premises  and 
learn  the  history  of  the  San  Jose  scale  on.  the  place.  How 
much  damage  has  it  done  from  year  to  year?  How  much 
has  been  expended  in  fighting  it?  What  and  how  many 
trees  have  been  killed  by  it?  In  connection  with  the  field 
and  laboratory  work  search  for  natural  enemies,  fungus  or 
insect.    Make  a  list  of  food  plants  upon  which  the  scale  is 


SPECIAL  PROBLEMS  OF  INSECT  CONTROL      159 

found  in  your  neighborhood.  Compare  results  of  different 
methods  of  combating  it.  From  the  data  obtainable  can  you 
foretell  the  probable  result?  Will  the  home  fruit  trees  be 
killed  and  the  fruit  industry  confined  to  commercial  orchard- 
ists  who  will  care  for  their  trees  ? 

Gypsy  moth.    This  pest  is  a  European  species.    It  was  in- 
troduced into  this  country  in  1869  by  a  Frenchman  who  was 


Fig.  78.   Outdoor  laboratory  work 
Class  inspecting  a  local  nursery  for  San  Jose'  scale 

attempting  to  improve  our  native  silkworms.  Through  acci- 
dent the  insects  escaped,  but  although  the  fact  was  reported, 
the  grave  danger  was  not  realized  until  twenty  years  later. 
From  a  single  nest  in  Medford,  Massachusetts,  the  pest  spread, 
slowly  at  first,  and  then  like  wild  fire,  over  the  towns  and  for- 
ests of  New  England.  Millions  of  dollars  have  been  expended 
in  its  control,  yet  hundreds  of  acres  of  forest  have  been  de- 
stroyed. A  report  of  1897  says,  "At  the  present  time  there 
can  be  little  doubt  that  the  extermination  of  the  insect  is 


160  CIVIC  BIOLOGY 

possible  and  that  it  will  be  only  a  question  of  a  few  years  " ; 
but  now,  nearly  fifteen  years  later,  it  is  still  gaining  ground. 

Since  a  large  portion  of  the  year  is  passed  in  the  egg  stage, 
this  is  the  natural  time  for  extermination.  The  egg  masses 
are  conspicuous  dark  yellow  splotches,  and  in  a  badly  infested 
region  may  be  found  anywhere,  — -  on  fence  or  stone  wall, 
under  porches,  among  dead  leaves,  —  although  the  first  and 
most  common  position  is  the  trunk  and  branches  of  trees.  The 
rapid  fire  which  is  sometimes  sent  through  woods  and  under- 
brush to  destroy  other  pests  has  no  marked  effect  on  these 
eggs.  Attempts  to  remove  the  egg  masses  by  scraping  have 
proved  equally  ineffective,  for  eggs  become  scattered  in  the 
process  and  hatch  as  readily  as  ever. 

Saturating  the  egg  clusters  with  the  following  mixture : 
creosote  oil  50  per  cent,  carbolic  acid  20  per  cent,  spirits  of 
turpentine  20  per  cent,  coal  tar  10  per  cent,  is  the  method  of 
extermination  recommended  by  state  authorities.  It  is  applied 
with  a  small  brush.  This  treatment  must  find  every  egg  mass, 
and  therefore  must  be  begun  the  instant  the  presence  of  the 
insect  is  known.  The  insatiable  appetite  of  caterpillars  makes 
so  omnivorous  a  creature  as  the  gypsy  moth  even  more  dreaded, 
for  when  one  feeding  grojind  is  exhausted,  a  fresh  one  over  the 
fence  or  across  the  road  is  quickly  attacked.  Thus  the  pest 
moves  on,  leaving  every  twig  stripped  behind  it. 

Every  effort  must  be  made  to  keep  the  pest  within  its  pres- 
ent limits.  The  female  imago  does  not  fly ;  therefore  distri- 
bution is  effected  by  the  caterpillars  which  frequently  spin 
down  from  the  trees  and  fall  upon  passing  conveyances,  or  by 
egg  masses  which  are  overlooked  on  lumber  or  are  carried  in 
various  ways. 

Brown-tail  moth.  The  problem  of  the  brown-tail  moth  is 
one  of  even  greater  importance  to  the  country  at  large  be- 
cause of  the  greater  rapidity  of  distribution.  Both  male  and 
female  are  strong,  swift  flyers,  and  eggs  may  be  deposited  at 


SPECIAL  PROBLEMS  OF  INSECT  CONTROL   161 


great  distances  from  the  original  colony.  Windstorms  also 
aid  in  furthering  the  flight,  and  steam  cars  and  trolleys  trans- 
port these  pests.  Besides  the  injury  to  orchard,  shade  tree, 
and  forest,  the  brown-tail  caterpillar  inflicts  serious  pain  upon 
many  persons.  This  is  caused  by  fine  hairs  which  pierce  the 
skin,  the  irritation  becoming  severe  enough  in  some  cases  to 
cause  illness.  A  free  use  of 
vaseline  will  give  relief. 

The  brown  tail  cannot  be 
controlled  by  an  attack  upon 
the  eggs,  since  they  are  usually 
on  the  leaves  and  for  a  short 
time  only.  Spraying  is  em- 
ployed to  destroy  the  swarm- 
ing caterpillars,  but  the  most 
effective  method  is  destruc- 
tion of- the  winter  nests.  These 
are  conspicuous  on  the  tips  of 
branches  between  August  and 
iVpril.  They  may  then  be  cut 
with  pole  shears,  and  must  be 
ear ef idly  coUeeted  and  burned. 

Parasites.  The  great  aim 
in  the  attempt  at  control  of 
any  pest  is  to  discover  its  nat- 
ural enemy.     In  the  case  of 

insects  like  the  gypsy  and  brown-tail  moths,  a  series  of  para- 
sites is  necessary,  for  the  parasitic  insects  restrict  themselves 
to  one  stage  only  in  the  development  of  their  host.  The  insect 
which  attacks  the  egg  takes  no  notice  of  the  caterpillar,  and 
the  insect  which  attacks  the  caterpillar  is  never  found  upon 
pupse.  Several  native  parasitic  insects  are  known  to  attack 
these  pests,  and  many  have  been  imported ;  but  as  yet  the 
series  is  not  complete  and  has  failed  of  effective  control. 


Fig.  79.    Brown-Tail  Moths 

Four  egg  masses  and  two  moths  laying, 

July  10.    Photograph  by  Katharine  E. 

Dolbear 


162 


CIVIC  BIOLOGY 


Comparison  of  Gypsy  and  Brown-Tail  Moths 


Gypsy  Moth 

Eggs.  August  to  May.  On  the 
trunks  and  branches  and  every- 
where^ especially  on  undersides 
and  inner  surfaces  of  objects. 

Masses.  Light  brown,  long,  broad, 
about  the  size  of  a  silver  quarter. 
300-1400  eggs. 

Caterpillar.  May  to  August.  On 
wnJerside  of  leaves.  Night  feed- 
ers. Cluster  in  shelter  during 
the  day. 

Winter  form.    Egg. 


Full-grown.  Two  and  one-half  to 
three  inches  long.  Rows  of  con- 
spicuous spots  on  the  back  — 
blue  near  the  head,  red  on  posterior 
part  of  the  body.  Hairy  tufts 
on  the  sides. 

Pupa.  Late  July.  Found  in  some 
places  as  e^g  masses.  Dark 
brown  female  larger  than  the 
male. 

Moth.  Female,  white  with  brown 
markings.  Spread  of  wing,  from 
two  to  three  inches.  Never  goes 
far  from  pupa  case.  Male  smaller, 
brown. 


Brown-Tail  Moth 

Eggs.  July.  Seldom  on  trunk  or 
branch.  Generally  on  underside 
of  leaf. 

Masses.  Smaller  than  the  gypsy, 
more  elongated,  brighter,  red- 
dish brown  color.  About  300 
eggs. 

Caterpillar.  Hatched  in  August. 
On  upper  side  of  leaves  in  clus- 
ters.   Day  feeders. 

Winter  form.  Caterpillar  in  nest. 
Nest  four  to  six  inches  long, 
composed  of  leaves  and  silk, 
contains  about  250  caterpillars. 
Emerge  in  April,  attack  bud, 
blossom,  and  foliage  of  fruit 
trees,  and  then  move  to  others. 

Fulh-grown.  One  and  one-half  to 
two  inches  long.  Broken  white 
stripe  on  each  side  of  back,  two 
red  spots  near  posterior  end. 
Hairy  tufts  on  the  sides. 

Pupa.  Late  June.  Five  eighths  of 
an  inch  long.  Dark  brown,  with 
yellowish  hairs. 

Moth.  Pure  white.  Female  slightly 
larger,  with  conspicuous  bunch 
of  brown  hairs  at  tip  of  abdo- 
men. Spread  of  wing,  one  and 
one-half  inches.  Night  flyer, 
attracted  by  light. 


t  t  f 


3a 


5a 


HCT Oliver,  del. 


PLATE  i\.    ADULT  FEMALiiS  OF  Fl\  K   IMPORTANT  TICKS* 


CHAPTER  XV 

ARACHNIDS.     PROBLEMS  OF  SPIDERS,  MITES,  AND  TICKS 

Prices  would  be  higher,  the  demand  greater,  and  the  odium  attached  to 
ticky  cattle  at  the  stockyards  removed.  Pure-bred  Northern  cattle  could  then 
be  brought  into  the  South  to  improve  the  native  breed,  without  danger  of 
death  from  Texas  fever ;  Southern  cattle  could  enter  the  show  rings  of  the 
North  without  restriction  ;  and  the  total  cost  of  tick  extermination  would 
be  far  less  than  the  amount  saved  in  the  first  year  after  it  had  been  accom- 
plished.—  John  R.  Mohler,  1914 

Closely  allied  to  insect  problems  are  those  of  the  arachnids. 
This  group  includes  scorpions,  spiders,  mites,  and  some  of  the 
ticks.  Interesting  as  they  are,  scorpions  and  spiders  are  far  sur- 
passed in  economic  importance  by  the  insignificant  mites  and 
ticks.  Among  the  latter  are  the  cattle  tick  (carrying  the  germ 
of  Texas  fever),  the  sheep  scab  mite,  mites  which  attack  poultry, 
and  the  red  spiders  and  harvest  mites  which  infest  vegetation. 

Since  arachnids  are  often  mistaken  for  insects,  compare  any 
common  insect  and  spider,  noting  their  similarities  and  dif- 
ferences.   Make  a  diagrammatic  sketch  of  each. 

Similarities.  Both  insects  and  araclmids  are  ringed  or  jointed 
aninials.  Both  are'  tracheates,  though  a  few  of  the  arachnids, 
particularly  spiders,  have  also  pulmonary  sacs. 

Differences.  These  will  be  found  in  the  relation  of  head 
and  body,  the  number  of  legs,  presence  of  antennae,  com- 
parison of  palpi. 

*  Five  species  are  shown,  enlarged  and  natural  size.  1  and  1  a,  adult 
female  cattle  (Texas-fever)  tick ;  2,  growth  stages  and  variations  in  color 
of  this  tick  ;  3  and  3  a,  Rocky  Mountain  spotted-fever  tick,  adult  female  ; 
4  and  4  a,  female  dog,  or  wood,  tick  ;  5  and  5  a,  female  European  dog  tick  ; 
6  and  6  a,  female  chicken  tick.  (Reproduced  from  plates  issued  by  the 
United  States  Department  of  Agriculture  and  the  United  States  Public 
Health  Service.) 

163 


164 


CIVIC  BIOLOGY 


The  larger  arachnids,  in  spite  of  their  bad  reputation  and 
terrifying  appearance,  are  comparatively  harmless.  Even  those 
of  the  poisonous  varieties,  tarantulas  and  scorpions,  make  no 

attack  upon  man  un- 
less frightened  or  mo- 
lested. Their  economic 
importance  is  not  con- 
sidered great,  though 
since  they  are  insectiv- 
orous, they  may  be  dis- 
tinctly beneficial. 

The  smaller  arach- 
nids, mites  and  ticks, 
cause  great  destruction 
of  vegetable  and  animal 
life.  They  are  charac- 
terized by  an  unseg- 
mented  body,  the  abdo- 
men as  well  as  the  head 
being  joined  to  the  tho- 
rax. While  we  must 
not  overlook  the  service 
of  some  species  as  scav- 
engers, we  are  con- 
cerned much  more  with 
them  as  })arasites  upon 
living  animals  and 
plants. 

Red  spider  —  Tetra- 
nychid(£i "  four-clawed." 
This  greenhouse  pest  is  found  both  indoors  and  out,  and  on 
various  plants  and  trees.  It  is  one  of  the  commonest  families, 
containing  sixty  species.  The  red  spiders  are  most  trouble- 
some in  times  of  drought  and  are  found  chiefly  on  the  underside 


Fk 


80.  Ilarvestineii  clearing  the  plant  lice 
from  a  grapevine 

Photograph  by  the  author 


PROBLEMvS  OF  SPIDERS,  MITES,  AND  TICKS     165 

of  leaves.  So  minute  are  they  that  a  smgle  one  is  scarcely 
visible  to  the  naked  eye,  and  they  are  often  not  noticed  until 
the  plant  is  badly  infested. 

They  pierce  the  surface  of  the  leaf  and  suck  its  juices,  and 
very  soon  the  plant  begins  to  appear  yellow  and  sickly.  When 
it  is  practicable  the  garden  hose  will  exterminate  these  pests. 
Under  other  conditions  spraying  with  fish  oils  or  soap  solution 
is  effective. 

Clover  mite  —  Bryobia  pratensis.  As  the  name  indicates,  these 
mites  are  found  chiefly  upon  clover,  but  also  on  apple  and 
peach  trees,  cottonwoods  and  arbor  vitse,  and  even  on  boards, 
stones,  and  fences.  During  the  fall  and  winter  they  appear 
also  on  plum,  almond,  poplar,  and  elm  trees,  and  frequently 
leave  vegetation  entirely  and  become  very  troublesome  in 
houses. 

Of  species  found  upon  animals,  there  are  some  which  can- 
not be  considered  a  real  menace  to  health,  yet  they  are  ex- 
tremely irritating  and  troublesome.  The  most  common  of  these 
are  harvest  mites  and  wood  ticks,  the  former  being  one  of 
the  smallest  of  mites,  a  mere  pin  point  of  red,  and  the  latter 
one  of  the  largest  of  ticks,  reddish  brown,  a  quarter  of  an 
inch  in  length  and  swelling,  as  it  feeds,  to  the  size  of  an  olive. 

Harvest  mite  —  Tromhidium  holosericeum.  When  in  the  larval 
stage,  these  are  the  ''chiggers"  of  the  Middle  States.  During 
early  summer  harvest  mites  will  be  found  on  grasslands  and 
sandy  slopes,  or  in  the  woods.  They  can  be  seen  most  easily 
in  July,  when  the  eggs  are  being  laid,  and  that  is  the  time 
also  when  they  begin  to  attach  themselves  to  any  passing 
animal.  The  creatures  of  the  woods,  especially  moles  and 
hares,  are  sometimes  literally  infested  with  them,  and  dogs, 
cats,  horses,  and  cows  often  show  signs  of  intense  itching 
from  them.  In  some  localities  there  are  few  people  who  have 
not  felt  their  presence.  Sulphur  ointment  or  friction  with  a 
cloth  dipped  in  benzine  or  strong  alcohol  will  give  speedy 


166 


CIVIC  BIOLOGY 


relief,  if  applied  soon  after  exposure  and  before  the  mites 
have  become  embedded  in  the  skin. 

Itch  mites  —  Sarcoptes  scabiei  (scabere,  "to  scratch ").  These 
mites  have  long  been  a  terror  to  man.  They  multiply  at  the 
rate  of  15,000,000  from  a  single  pair  during  the  season,  are 
easily  passed  from  one  animal  to  another,  and  are  extremely 
difficult  to  control.    There  are  many  varieties  of  itch  mites, 

differing  in  size  ac- 
cording to  the  thick- 
ness of  skin  of  the 
animal  they  attack. 
The  pig,  horse,  wolf, 
goat,  camel,  sheep, 
dog  —  each  has  its 
own  variety  (de- 
creasing in  size  in  the 
order  here  given) 
and  the  human  mite 
is  the  smallest  of  all. 
The  punctures  made 
in  the  skin  by  mites 
are  soon  covered 
with  a  crust,  the  eggs 
bemg  found  beneath 
it.  The  human  mite 
is  best  held  in  check  by  warm  baths  with  free  use  of  soap 
followed  by  an  application  of  sulphur  ointment.  The  same 
treatment  is  equally  good  for  dogs. 

Sheep-scab  mite.  — Psoroptes  communis  (var.  ovis).  This  para- 
site is  distributed  over  the  entire  world  and  has  proved  so 
destructive  that  most  countries  have  passed  laws  to  prevent 
its  importation  or  spread.  With  intelligent  cooperation  in  the 
use  of  precautions  and  methods  of  treatment  now  understood, 
sheep  scab  could  soon  be  eradicated. 


Fig.  81.   Egg  cocoons  of  spiders  on  burdock 
Photograph  by  Dr.  J.  P.  Porter 


PROBLEMS  OF  SPIDERS,  MITES,  AND  TICKS     167 

The  poultry  mite  —  Dermanyssus  gallince.  This  is  a  vicious- 
looking  creature  when  seen  under  a  microscope.  In  color  it 
varies  from  yellowish  white  to  blood  red  when  fully  gorged. 

Its  presence  is  sometimes  not  suspected,  for  it  is  a  night 
worker,  and  during  the  day  it  disappears  into  cracks,  especially 
in  the  ceilmgs.  If  extremely  numerous,  adults  may  be  found 
on  the  fowl,  but  generally  not  even  the  indications  of  their 
punctures  are  visible  and  only  the  condition  of  the  poultry 
shows  their  existence.  There  is  danger  of  this  mite  being 
carried  to  the  stable,  if  near  by,  and  the  effect  upon  horses  is 
sometimes  serious.  Absolute  cleanliness  in  the  henhouse  is 
the  price  of  freedom  from  this  pest. 

The  Rocky  Mountain  spotted-fever  tick.  —  Dermacentor  ve- 
nustus.  The  germs  of  spotted  fever  are  carried  from  native 
wild  animals  to  man  by  the  bite  of  this  tick.  The  life  history 
of  the  tick  consists  of  four  stages  —  the  egg,  "  seed  "  or  larva, 
nymph,  and  adult  —  and  occupies  from  one  to  three  years. 
Failure  to  find  a  host  during  any  of  the  three  active  stages 
results  in  death  of  the  tick  by  starvation,  and  the  discovery 
that  earlier  stages  are  largely  dependent  on  the  rodents  of 
the  region  has  resulted  in  a  plan  of  cooperative  effort  to  ex- 
terminate rodents  and  ticks  together.  Since  most  of  the  host 
species  are  destructive  to  agriculture,  the  work  is  doubly 
worth  doing.  "  Cooperation  by  all  landowners  in  a  district 
is  essential  to  success  of  any  extensive  campaign  of  rodent 
destruction."  1  It  has  also  been  observed  that  sheep  rid  land 
of  this  tick,  and  this  suggests  that  they  might  prove  useful 
against  chiggers  and  other  ticks. 

Cattle  tick  —  Margaropus  annulatus.  The  germ  of  Texas 
fever  is  now  known  to  be  carried  by  this  tick.  The  loss  to 
the  South  as  a  result  of  this  disease  has  been  estimated  by  the 

"^  Clarence  Birdseye,  "  Some  Common  Mammals  of  Western  Montana  in 
Relation  to  Agriculture  and  Spotted  Fever."  Farmer'' s  Bulletin  No.  484. 
AVashino:ton,  1912. 


168  CIVIC  BIOLOGY 

govemmeiit  to  be  |63,250,000  annually.  Texas  fever  does 
not  become  established  in  the  North,  because  the  tick  cannot 
survive  the  winter;  nevertheless  it  frequently  appears  there. 
Northern  cattle  have  been  attacked  by  it  as  early  as  thirteen 
days  and  as  late  as  ninety  days  after  the  tick-bearing  cattle 
have  passed  tlirough  the  locality.^  Eight  species  of  ticks  have 
been  found  on  cattle  in  this  country,  but  only  Margaropus 
annulatus  carries  the  germ  of  Texas  fever.  It  may  be  distin- 
guished readily  from  the  other  seven  by  its  tiny  reddish-brown 
head,  contrasting  with  its  dull  yellow  or  even  olive-brown 
body,  and  by  its  shape  and  size.  The  body  is  broadly  oblong, 
sometimes  reaching  fifteen  millimeters  in  length,  and  shows 
irregular  markings  of  yellow.  Notice  differences  between 
Margaropus  annulatus  and  comparatively  harmless  ticks  com- 
mon on  cattle  (Plate  IV). 

Dog  tick  or  wood  tick  —  Dermacentor  electus,  Aristotle  calls 
the  wood  tick,  dog  tormentor.  Whoever  has  experienced  one 
on  himself  knows  well  the  firm  grip  which  it  takes,  and 
appreciates  the  name.  Force  in  removing  the  tick  results 
either  in  pullmg  away  the  body  and  leaving  the  head  still 
attached,  or  in  carrying  away  a  bit  of  flesh  with  the  head. 
The  better  way  is  to  touch  the  tick  with  a  drop  of  kerosene 
or  turpentine.    It  then  loosens  its  hold  and  is  easily  removed. 

These  are  only  a  few  of  the  mites  and  ticks.    Frequently 

one  comparatively  unknown  is  discovered  to  be  the  cause  of 

some  baffling  disease  or  a  possible  check  to  some  pest.    Your 

observations  now  may  assist  in  the  future.    Keep  a  record  of 

each  new  parasite  you  find  —  insect  or  arachnid  ;  note  name 

of  specimen,  date,  locality,  host  (plant  or  animal  upon  which 

it  is  found),  and  any  facts  likely  to  be  useful. 

1  This  necessitated  drawing  the  quarantine  line  of  1891  across  the  conti- 
nent from  southern  California  to  southern  Virginia.  This  line  has  been 
pushed  southward  since  active  tick  eradication  was  begun  in  1906,  and  coop- 
eration of  stockmen  must  eventually  relieve  the  entire  South.  The  problem 
is  one  for  serious  study  in  all  schools  within  or  near  tick-infested  territory. 


CHAPTER  XYI 
AMERICAN  MAMMAL  rilOBLEMS 

Each  form  of  animal  or  plaiit  .should  be  looked  upon  as  an  experiment  in 
making  a  machine  which  shall  best  tit  its  environment  and  most  effectively 
do  the  work  required  of  it.  The  fit  live  ;  the  unfit  are  relegated  to  the  bio- 
logical scrap  heap,  that  is,  become  extinct.  Care  of  offspring  and  protection 
from  the  elements  are  prime  factors  in  fitness  to  survive.  Mammals  excel  in 
both  of  these  functions  and  characters,  and  while  the  feather  is  as  light  and 
perhaps  more  beautiful,  hair  is  tougher  and  stands  harder  wear,  and  milk 
carried  by  the  mother  is  a  safer  provision  for  the  young  than  food  packed 
in  the  shell  of  an  egg.  Above  all,  the  intelligence  which  fashions  adaptable 
protection  from  the  elements,  clothes  and  liouses,  caps  the  climax  of  purely 
biological  fitness. 

Mammals.  This  group,  to  which  man  himself  belongs, 
ranks  highest  in  the  scale  of  animal  life.  Its  various  forms 
dominate  easily  sea  and  land  and  yield  only  to  birds  domhi- 
ion  of  the  air.  Every  one  knows  a  bird  at  sight,  but,  unlike 
this  compact  group,  mammals  differ  extremely  in  structure 
from  fishlike  porpoises  and  whales  to  birdlike  bats.  In  gen- 
eral, hair  is  as  characteristic  of  mammals  as  feathers  of  birds ; 
and  aside  from  a  few  freak  forms,  like  tlie  Australian  duck- 
bill (^Omithorpichus  paradoxus,  '' bird -nosed  paradox  "),  which 
lays  eggs  and  incubates  them  like  a  bird,  mammals  agree  in 
nourishing  the  young  with  milk. 

Among  the  more  important  problems  relathig  to  American 
mammals  are  the  following: 

1.  Extermination  of  predacious  forms  as  the  continent  has 
been  opened  up  to  settlement  —  panthers,  bears,  lynxes  and 
wild  cats,  wolverines,  wolves,  minks,  skunks,  and  weasels. 

2.  Utilization  of  native  wild  animals  —  bison,  elk,  moose, 
deer,  antelope,  mountain  sheep  and  goats,  hares  and  rabbits. 

169 


OPOSSUMS  AND 
KANGAROOS 


Fig.  82.    Orders  of  nianiinals,  with  habitats 
170 


AMERICAN  MAMMAL  PKOBLEMS  171 

These  have  been  an  important  source  of  food  during  the  early 
settlement  of  the  country. 

3.  Trapping  fur-bearing  mammals  —  beaver,  otter,  marten, 
sable,  badger,  muskrat,  moles,  and  others. 

5.  Efforts  to  prevent  the  total  extinction  of  valuable  species. 

This  last  feature  of  the  American  problem  has  been  late  in 
developing. 

Our  destruction  of  animal  game  resources  is  commonly 
spoken  of  as  wanton,  and  in  many  instances  this  is  undoubtedly 
true.  Still  the  problems  are  not  so  simple  as  they  often  appear ; 
for  example,  thousands  of  bison  were  shot  for  the  mere  sport 
of  shooting,  and  the  species  is  now  practically  extinct  in  the 
wild  state.  This  seems  a  great  waste,  but  it  is  impossible  to 
use  the  same  range  for  both  bison  and  domestic  cattle,  and 
cattle  are  much  more  valuable.  The  bison  herds  swept  the 
range  cattle  with  them  in  their  migrations  and  strewed  settlers' 
fences  over  the  plains.  When  full-grown  they  are  not  amen- 
able to  ordinary  means  of  control  and  probably  could  not  be 
profitably  domesticated.  Even  tame  buck  deer  and  bull  elk 
are  dangerous  animals.  Rearing  the  bison  in  specially  fenced 
preserves  is  quite  a  different  matter,  and  has  proved  —  at, 
present  fancy  prices  for  robes  and  heads  —  a  profitable  indus- 
try. Both  the  United  States  and  Canada  have  undertaken  to 
thus  safeguard  the  species  from  extinction,  and  the  American 
Bison  Society  has  been  recently  organized  to  make  sure  that 
the  largest,  and  in  many  ways  most  picturesque,  American 
mammal  shall  never  entirely  disappear  from  the  earth. 

Those  in  charge  of  zoological  parks  and  private  forest 
preserves,  as  well  as  of  the  extensive  national  forest  reserva- 
tions, are  all  making  preservation  of  native  animals  a  strong 
feature  of  their  work.  Many  states  are  also  beginning  to 
legislate  to  prevent  extermination  of  valuable  animals.  Sev- 
eral states  derive  considerable  revenue  from  hunting  licenses, 
and,  in  order  to  attract  sportsmen,  must  maintain  the  supply 


172  CIVIC  BIOLOGY 

of  game.  Wild  deer  are  beginning  to  be  seen  in  eastern  ]Mas- 
sachusetts,  the  state  allowing  but  a  single  week  for  hunting 
them  and  paying  all  damage  which  they  cause  to  crops.  These 
damages  are  increasing,  however,  so  fast  that  it  is  a  serious 
question  whether  such  an  animal  should  be  allowed  to  range 
at  large  in  a  state  not  possessing  extensive  tracts  of  waste  land. 
State  forest  reservations,  private  hunting  preserves,  and  spe- 
cial parks  will  probably  solve  the  problem  in  such  a  manner 
that  the  species  will  be  preserved  and  the  people  permitted  to 
see  and  enjoy  them  in  their  native  haunts,  while  promiscuous 
damage  is  prevented. 

The  preservation  of  the  fur  seal  has  come  to  be  an  inter- 
national problem  which  is  engaging  in  its  solution  the  best  ex- 
perts of  England,  Russia,  Japan,  and  the  United  States.  There 
is  thus  a  good  chance  of  saving  a  great  industry  to  the  inter- 
ested nations  and  a  number  of  fine  species  of  seals  to  the  world. 

As  the  animals  have  been  trapped  off,  the  price  of  furs  has 
steadily  advanced,  until  the  rearing  of  fur-bearing  animals  — 
notably  the  silver  fox  —  is  becoming  a  paying  industry.  At 
present  prices  it  ought  to  be  possible  to  rear  many  of  our  fur- 
bearing  animals  at  enormous  profit.  "  The  beaver,''  says  Pro- 
fessor Shaler,  ''  particularly  the  North  American  form,  offers 
a  most  attractive  opportunity  for  a  great  and  far-reaching 
experiment  in  domestication.  On  this  continent,  at  least,  the 
creature  exhibits  a  range  of  attractive  qualities  which  is  ex- 
ceeded by  none  other  in  the  whole  range  of  the  lower  mam- 
malian life.''  Here  is  a  new  field  of  biological  interest, 
experiment,  and  human  advance  in  control  of  animal  life  which 
ought  to  appeal  to  boys  who  live  on  farms  affording  opportu- 
nities for  such  work.  Methods  of  caring  for  the  animals  in 
confinement  or  under  control  may  be  learned  to  advantage 
from  zoological  gardens ;  and  anything  in  the  way  of  local 
"  deer  farming  "  or  ''  fur  farming  "  should  be  studied  and 
reported  on  by  interested  members  of  the  class. 


CHAPTER  XVII 
THE  RAT  PROBLEM 

The  rat  is  the  worst  iiiaiiimalian  pest  known  to  man.  Its  depredations 
tliroughout  the  world  result  in  losses  amounting  to  hundreds  of  millions  of 
dollars  annually.  But  these  losses,  great  as  they  are,  are  of  less  importance 
than  the  fact  that  rats  carry  from  house  to  house  and  from  seaport  to  sea- 
port the  germs  of  the  dreaded  plague.  —  David  Laxtz,  ''The  Brown  Rat 
in  the  United  States,"  p.  9.  Bulletin  No.  33,  Biological  Survey,  United  States 
Department  of  Agriculture 

The  smell  of  mice  shall  be  in  their  nostrils  and  they  shall  die.  —  Old  saying 

To  pay  11,000,000  for  the  last  pair  of  rats  on  the  North 
American  continent,  after  the  Panama  Canal  is  cut  through, 
and  every  harbor  is  properly  sea-walled,  might  be  money  well 
expended.  The  warfare  which  has  been  going  on  for  thou- 
sands of  years  might  then  be  terminated  in  at  least  one  conti- 
nent —  and  may  not  all  good  Americans  unite  in  the  hope 
that  ours  may  be  the  first  continent  of  which  this  is  true  ? 

The  failure  of  all  attempts  to  deal  with  this  vile  enemy 
may  be  traceable  to  lack  of  a  vivid  realization  of  what  the 
"  last  pair  "  may  do  in  the  way  of  increase.  The  brown  rat 
may  breed  five  times  in  a  season  and  have  from  6  to  23  young 
at  a  litter.  Allowing  8  young,  the  increase  from  a  single  pair 
in  a  season  may  amount  to  880  ;  and  if  we  figure  10  in  a  litter, 
this  number  is  increased  to  1250.  In  three  years  with  only  6 
young  in  a  litter  Lantz  has  computed  the  possible  increase  at 
20,155,392.  From  these  data  it  is  clear  that  any  scientific 
method  of  dealing  with  this  problem  in  any  home  or  locality 
must  catch  the  last  pair,  and  also,  under  existing  conditions, 
insure  catching  the  first  pair  as  soon  as  it  comes. 

173 


174  CIVIC  BIOLOGY 

Damage  annually  caused  by  rats  has  been  figured  for  several 
countries  as  follows : 

Denmark $3,000,000 

France 40,000,000 

Germany 50,000,000  " 

England 73,000,0001 

United  States 100,000,000  2 

This  estimate  of  1100,000,000  worth  of  grain  is  based  on  the 
amount  actually  eaten  by  rats,  and  Lantz  maintains  that  they 
destroy  and  pollute  "  fully  as  much  as  they  consume."    But  a 


Fig.  83.    Common  brown  rat  and  mouse 
Photograph  by  the  author 

damage  tax  of  |200,000,000  levied  annually  on  cereal  crops 
is  by  no  means  the  whole  story.  The  poultry  industry  yields 
1600,000,000  annually,  and  rats  take  an  enormous  toll  of  eggs 
and  young  chicks.  "  I  have  known  them  to  take  nearly  all 
the  chicks  on  a  large  poultry  ranch,  and  in  the  same  neighbor- 
hood and  over  a  large  territory,  to  destroy  nearly  50  per  cent 
of  the  season's  hatching  "  (Lantz).  The  writer  learned  of  an 
instance  of  a  large  rat  killing  and  carrying  away  an  entire 
brooder  lot  of  over  two  hundred  newly  hatched  chicks  in  a 
single  night.    Ducks,  turkeys,  pigeons,  game,  and  song  birds 

1  Great  Britain  and  Ireland,  rural  damage,  and  does  not  include  losses 
in  towns  and  cities  and  that  inflicted  upon  shipping. 

2  For  destruction  of  grains  only. 


THE  RAT  PEOBLEM 


175 


suffer  likewise  from  their  attacks.  Finally  the  rat  is  the 
primary  boast  of  trichina  which  causes  so  much  damage  and 
loss  in  the  raising  of  swine.  One  of  the  prime  requisites  in 
all  such  industries,  if  they  are  to  be  conducted  with  safety 
and  success,  is  rat-proof  construction. 

The  depredations  of  rats  on  fruits  and  vegetables,  bulbs  and 
seeds  of  all  kinds,  and  all  manner  of  merchandise,  meats,  and 
stored  provisions  are  too  well  known  to  require  more  than 
passing  mention..   Buildings  are  damaged,  water  pipes  gnawed 


Fig.  84.    A  small  night's  work  for  a  rat 

Eleven  chicks  have  been  killed  and  dragged  into  the  hole  and  three  bitten  so  that 
they  died.   Photograph  by  the  author 

and  buildings  flooded,  the  insulation  of  electric  wires  de- 
stroyed, which,  together  with  matches  carried  into  their  nests 
and  ignited,  cause  numerous  fires.  "  It  is  conservative  to  place 
the  entire  yearly  loss  to  the  people  of  Washington  from  rats 
and  mice  at  $400,000  "  (Lantz).  For  Baltimore,  Lantz  esti- 
mates the  yearly  damage  at  $700,000 ;  and  for  cities  in  the 
United  States  of  over  100,000  inhabitants  these  studies  would 
indicate  an  annual  loss  of  |20,000,000. 

Black  death,  the  bubonic  plague,  beginning  in  China  in 
1334,  swept  westward  over  Europe,  and  in  that  single  epi- 
demic killed,  it  is  estimated,  25,000,000  people  in  Europe 


176 


CIVIC  BIOLOGY 


alone.  One  half  the  people  of  Italy  were  killed  by  it.  Whole 
villages  and  towns  were  left  without  a  livuig  inhabitant,  and 
cattle  ranged  at  will  among  the  unharvested  fields.  In  the 
recent  epidemic  it  is  estimated  that  the  plague  has  killed  hi 
India,  up  to  1907,  no  less  than  5,250,000.  It  has  gained  a 
foothold  in  this  country,  but  San  Francisco,  hi  the  most  thrill- 
ingly  interesting  civic  effort  ever  recorded  in  human  history, 
and  with  the  best  assistance  the  national  government  could 

give,  stamped  it  out  after 
taking  a  meager  toll  of 
seventy-seven  lives. 

"  He  died  of  the  plague  and 
all  my  family  with  him.  I  have 
no  home  or  wife  or  relation  to 
go  to  so  I  will  take  no  leave  this 
year." — Keply  of  a  native  sol- 
dier in  India  to  a  question  about 
his  brother. 

Bubonic  plague  in  man  is 
entirely  dependent  on  the  dis- 
ease in  the  rat. 

The  infection  is  conveyed 
from  rat  to  rat  and  from  rat  to 
-Lantz,  quoted  from  "Etiology 


Fig.  85.    Lead  pipe  gnawed  by  rats 

This  flooded  a  house  and  fortunately  caused 
only  $7  damage 

man  solely  by  means  of  the  rat  flea. 


and  Epidemiology  of  Plague,"  p.  93.    Calcutta,  1900 

Thus  a  bacterium,  an  insect,  a  mammal,  and  man  are 
bound  together  in  a  biological  relation  which  has  cost  the 
world  hundreds  of  millions  of  human  lives  and  centuries  of 
misery  and  horror.  At  last  modern  biology  has  discovered 
this  relation,  and  the  fact  that  an  intelligent  people  can  learn 
and  realize  its  truth  and  act  together  for  the  common  good  has 
made  the  difference  between  the  San  Francisco  epidemic  and 
that  of  India—  77  hves  to  5,250,000.  If  the  rat  did  no  other 
damage,  is  not  this  sufficient  reason  to  induce  every  citizen  of 
a  civilized  community  to  exterminate  rats  from  his  premises  ? 


THE  RAT  PROBLEM  177 

It  lias  l)eeii  said  that  "  of  all  liigliways  a  rat  loves  a  drain 
the  best."  Ovir  whole  sehenie  of  sanitation  depends  apon  the 
principle  of  washing  all  filth  and  disease  germs  into  onr  sew- 
ers. Here  then  we  have  an  animal  which  wallows  and  crawls 
and  swims  in  this  filth  and  nightly  distributes  it  over  exposed 
foods,  merchandise,  markets,  and  homes.  In  this  way  rats  are 
often  responsible  for  persistent  local  epidemics  of  any  disease 
whose  germs  are  washed  into  sewers,  —  typhoid,  diphtheria, 
scarlet  fever,  and  many  others.  These  facts,  together  with 
common  decency  and  intelligent  cleanlmess,  are  again  suffi- 
cient reasons  for  extermination  of  such  filthy  pests. 

On  all  three  counts,  therefore,  —  general  destrnctiveness, 
carriers  of  Black  death,  distributers  of  disease  and  filth  — 
rats  deserve  absolute  extermination.  They  were  formerly  con- 
sidered valuable  as  scavengers,  but  modern  methods  of  sani- 
tation are  thwarted  by  them,  and  these  have  rendered  their 
further  services  in  this  line  doubly  undesirable. 

The  simple  duty  of  every  citizen  is  to  exterminate  the  rats 
from  his  own  premises.  Modern  methods  —  traps,  poisons 
and  poisonous  gases,  concrete  and  rat-proof  construction  — 
render  this  entirely  possible,  and  at  a  fraction  of  the  cost 
which  the  presence  of  the  pests  yearly  entails. 

All  methods  of  driving  rats  away,  scattering  them  among 
the  neighbors,  accomplish  no  real  good  and  are  besides  uncivic. 

Trapping  is  at  once  the  safest  and,  for  boys,  the  most  edu- 
cative method  of  keeping  a  home  free  from  rats.  It  is  no  more 
expensive  and  much  more  interesting  to  keep  traps  set  all  the 
time  than  to  allow  them  to  be  lying  idle.  If  we  could  fire  a 
pistol  that  could  be  heard  across  the  continent,  and  from  that 
day  on  have  all  the  boys  of  the  country  keep  all  the  idle  rat 
and  mouse  traps  set  and  baited  in  the  most  likely  places 
about  their  homes  all  the  time,  the  battle  would  be  nine 
tenths  won.  Stores,  mills,  stables,  factories,  depots,  and 
wharves  could  then  deal  with  their  own  problems  effectively 


178 


CIVIC  BIOLOGY 


and  not  have  the  constant  stream  of  rat  and  mouse  immiscra- 
tion  from  surrounding  homes. 

To  work  for  days  and  finally  outwit  a  wise  old  rat  and 
catch  him  often  gives  one  a  game  and  a  story  almost  as  instruc- 
tive in  animal  cunning  as  that  of  old  Lobo  Rex  Currump?e. 
Being  chiefly  nocturnal,  and  living,  as  they  do,  in  the  total 
darkness  of  burrows  and  drains,  rats  sense  danger  mainly  by 
smell,  and  the  smell  of  man,  his  archenemy,  will  scare  a  rat 
away  from  a  trap  recently  handled.  But  leave  the  trap,  care- 
fully covered  with  earth  or  bran  or  loft  sweepings,  in  a  natu- 
ral runway  or  at  the  mouth  of  a  burrow  a  week,  the  man 

scent  disappears,  the  wisest 
old  rat  has  a  moment  of 
absent-mindedness,  and  the 
last  one  "  puts  his  foot  in  it." 
A  study  of  rat  traps  is 
interesting,  but  is  apt  to 
suggest  that  their  manufac- 
turers are  chiefly  concerned 
with  making  something 
which  will  not  exterminate 
their  business  by  catching  rats.  All  authorities  to  the  con- 
trary, notwithstanding,  the  writer,  after  ten  years'  active  study 
of  the  problem,  would  discard  all  rat  traps  which  depend  upon 
being  baited,  except  the  cage  or  box  traps  to  be  described 
below.  Give  him  an  old-fashioned  steel  spring  trap,  and,  by 
keeping  it  set  year  in  and  year  out,  he  will  guarantee,  with  the 
aid  of  other  methods  to  be  described,  to  catch  the  last  and  the 
first  rat  on  any  home  premises.  This  does  not  apply  to  mouse 
traps  which  require  baiting,  and  which,  if  kept  baited  and  set 
all  the  while,  insure  catchmg  the  last  and  first  mouse  in  any 
house  or  barn. 

If  the  focal  method  described  below  cannot  be  adopted,  a 
French  cage  trap  may  prove  of  some  use  about  a  home,  if  it  is 


Fici.  86.    A  durable  and  effective  trap 


THE  KAT  PROBLEM  179 

kept  well  baited  all  the  time,  and  open.  As  soon  as  it  is  noted 
that  the  rats  are  feeding  in  it  freely,  close  the  trap  end  and 
make  a  catch. 

Poisons  are  rather  "  unbiological "  and  require  some  care  in 
handling.  The  Department  of  Agriculture  has  recommended 
barium  carbonate  as  the  cheapest  and  safest  poison  to  use  for 
rats  and  mice.  It  is  tasteless,  and  in  the  small  quantities  used 
is  not  dangerous  to  domestic  animals.  Another  advantage  is 
that  it  is  slow  in  acting  and  the  vermin  leave  the  premises  to 
die.  Mix  oatmeal  with  one  eighth  of  its  bulk  of  the  poison 
into  a  stiff  dough  with  water,  and  place  a  teaspoonful  in  a 


Fig.  87.   A  good  design  for  a  runway  trap 

These  traps  were  so  poorly  made  that  they  were  likely  to  fly  to  pieces  when 

snapped,  and  never  caught  a  good-sized  rat  for  the  author  until  he  had  put  in  a 

row  of  tack  points  along  the  end  of  the  bottom  board 

plate  about  likely  places.  Or  moisten  a  slice  of  bread  and  rub 
in  a  quantity  of  the  barium  powder  on  both  sides,  spreading 
butter  over  it ;  cut  into  inch  cubes  and  place  in  the  runways. 
Or  mix  two  teaspoonfuls  of  the  barium  with  an  egg,  thicken 
to  a  stiff  paste  with  oatmeal,  corn  meal,  or  bread  crumbs,  and 
distribute  as  before.  Pieces  of  raw  Hubbard  squash  with  the 
poison  rubbed  well  into  all  the  cut  surfaces,  and  with  cuts 
made  in  the  flesh  and  filled  with  it,  make  excellent  baits.  It 
is  well  to  change  the  kind  of  bait  and  at  first  to  feed  freely 
with  the  same  material  unpoisoned,  and  even  then,  according 
to  the  writer's  experience,  you  will  not  succeed  in  fooling  the 


180 


CIVIC  BIOLOGY 


last  old  wise  ones.  Above  all,  use  clean  scalded  dishes  and 
utensils  and  avoid  all  possible  taint  of  man-smell  on  the  bait. 
Arsenic  is  one  of  the  most  common  ingredients  of  rat  poisons 
and  has  the  advantage  also  of  being  tasteless  and  of  causing 
intense  thirst  so  that  the  animals  leave  the  premises  m  search 
of  water.  It  may  be  used  in  combhiation  with  any  of  the  baits 
described  above.  In  mixing  with  corn  or  oatmeal  take  one 
twelfth  by  weight  of  the  poison.  In  putting  the  above  poisons 
in  houses  or  barns  be  sure  to  have  no  water  accessible  inside 
the  buildings ;  but  leave  doors  and  windows  open,  and,  if  a 
pan  of  water  is  sunk  in  the  ground  in  the  yard,  rats  and  mice 


Fig.  88.   The  poison  box 

The  inner  box,  where  the  bait  is  put,  should  he  about  4-6  inches  smaller  in  hori- 
zontal dimensions.    The  strip  (^  +  X 1  inch,  is  nailed  all  around  the  bottom  of  the 
larger  box  to  prevent  scattering  of  iwisoned  material.    Bait  with  pieces  too  large 
to  be  carried  out.   Leave  holes  in  lower  corners  small  for  rats  to  enlarge 

in  numbers  may  be  seen  dying  and  dead  around  it.  Tliey  even 
lose  all  fear  of  man  and  crawl  to  the  water  to  drink  in  broad 
daylight,  and  commonly  remain  at  the  water  until  they  die. 

To  destroy  rats  on  farms.  Each  evening  when  tlie  cows  are  milked 
l>lace  a  little  fresh  milk  in  a  shallow  pan  where  the  rats  can  get  it. 
C'ontinue  this  for  a  week  or  more  until  the  rats  get  bold  and  impatient 
to  get  at  it.  Then  mix  arsenic  with  the  milk  and  await  results.  This 
plan  is  said  to  entirely  clean  a  barn  of  rats.  —  Quoted  by  Lantz  from 
E.  H.  Reihl,  in  Colman's  Rural  World,  January  29,  1908 

Strychnine  acts  so  quickly  that  there  is  danger,  when  used 
about  buildmgs,  that  the  animals  may  die  in  the  walls.    In 


THE  RAT  PROBLEM  181 

other  places  it  may  be  used  very  effectively,  and  still,  on 
account  of  its  intensely  bitter  taste,  it  seldom  catches  the  sly 
old  ones.  Stryclmized  grain  used  in  poisonmg  sparrows  is 
equally  effective  for  rats  and  mice  (|^  oz.  strychnia  sul- 
phate dissolved  in  l  pint  of  boiling  water,  thoroughly  stirred 
into  2  quarts  of  cracked  corn  or  wheat,  dried  and  labeled 
and  stored  safely  for  use).  The  writer  has  been  told  of 
clearing  a  barnyard  and  large  stable  by  first  feeding  the 
rats  with  raw,  unbroken  eggs,  then  substituting  eggs  heavily 
charged  with  strychnine,  the  crystals  of  the  poison  being 
pushed  through  small  holes  in  the  shells.  The  ground  near 
these  eggs  was  described  as  ''  strewn  with  dead  rats." 

Phosphorus  pastes  commonly  sold  as  rat  and  mouse  poisons 
cannot  be  recommended,  as  they  are  too  likely  to  cause  fires. 
The  other  ingredient,  glucose,  is  likely  to  be  leached  or  w^eath- 
ered  away,  leaving  the  phosphorus  strong  enough  to  ignite 
spontaneously,  and  lumps  of  the  material  may  be  carried  by 
rats  from  perfectly  safe  places  —  in  a  cemented  cellar  —  up 
into  the  nests  anywhere  in  the  building.  Even  fields  of  grain 
have  been  fired  in  this  way. 

Fumigation  with  poisonous  gases  is  perhaps  the  most  effec- 
tive method  of  dealing  with  vermin  that  burrow.  It  is  such 
sport  to  absolutely  exterminate  rats  from  fields,  dumps,  poultry 
yards,  and  cellars  that  the  game  is  worth  the  expense. 

C  arbon  bisulphide  is  the  agent  most  commonly  u sed.  Moisten 
a  tuft  of  cotton  or  a  rag  the  size  of  an  egg  with  about  a  table- 
spoonful  of  the  bisulphide,  push  it  down  the  hole,  and  tamp 
tightly  with  earth.  If  the  hole  is  dug  out,  and  remains  inhabited, 
—  which  can  be  ascertained  by  filling  the  mouth  with  earth  a 
few  times,  —  repeat,  using  a  double  dose.  Carbon  bisulphide  is 
poisonous  to  breathe  and  is  not  only  highly  inflammable  but 
very  explosive ;  therefore  keep  all  lights  away  while  using. 

What  we  have  called  the  **  focal "  method  of  dealing  with 
civic  pests  consists  in  discovermg  something  which  attracts 


182  CIVIC  BIOLOGY 

them  above  everything  else.  This  is  a  method  of  attracting 
(focusing)  all  vermin  to  a  particular  place,  and  is  diametri- 
cally opposite  to  all  the  common  devices  for  "  driving  away  " 
or  scattering  our  pests  among  our  neighbors.  When  we  find 
something  which  will  attract  every  fly,  mosquito,  flea,  rat, 
English  sparrow,  stray  cat  to  a  certain  spot  and  catch  and 
kill  them  there,  the  work  of  control  or  extermination  will 
be  easy.  A  dog  is  a  natural  focus  for  every  flea  about  the 
premises.  Lather  him  with  soap  daily  or  once  a  week  for  a 
few  weeks  and  every  flea  will  be  exterminated. 

The  natural  focus  of  any  animal  is  its  preferred  food,  and 
for  rats  and  mice  about  the  home  this  is  the  granary,  feed 
room,  pantry,  or  storage  cellar.  It  is  only  necessary  to  make 
these  absolutely  rat  and  mouse  proof,  —  easily  accomplished 
now  with  cement,  sheet  metal,  or  wire  net,  —  and  then  leave  no 
food  exposed  outside  these  places,  and,  to  all  practical  intents 
and  purposes,  we  have  our  premises  rat  proof.  We  can  then 
easily  establish  a  focus  which  will  catch  or  kill  every  rat  or 
mouse  which  comes  to  us  for  food. 

Take  the  example  of  a  home  which  has  a  horse  and  cow 
and  poultry.  Each  place  will  present  its  own  problems,  but 
the  following  "scheme  will  apply  to  all  sorts  of  conditions. 

If  possible,  have  all  feed  for  poultry  and  stock  kept  in  a 
rat-  and  mouse-proof  feed  room.  The  wall  of  this  room  is 
tight,  preferably  steel  lath  and  cement,  except  a  space  six 
inches  high  by  one  foot  long  in  one  of  the  corners  against 
the  outer  wall  of  the  barn.  This  space  is  closed  by  both 
heavy  wire  net  of  one-quarter-inch  mesh  to  exclude  all  rats 
and  mice,  and  also  with  fine  wire  gauze  to  keep  out  all  in- 
sects. Rats  and  mice  seek  their  food  by  smell,  and  this 
opening  will  focus  to  that  place  all  the  animals  as  they  come 
to  the  premises,  if  no  other  food  is  accessible  anywhere  else. 
Keep  the  bag  of  Spratt's  dog  biscuit  and  the  poultry  scrap 
meat  and  a  bag  of  sunflower  seeds  near  this  hole,  and  if  rats 


THE  KAT  PROBLEM  183 

and  mice  are  coining  in  rapidly,  as  they  often  do  in  the  fall, 
keep  and  feed  well  for  a  while  a  female  rat  in  a  wire  cage 
against  this  opening.  Now  bore  a  hole  through  the  side  of 
the  barn  close  to  this  corner.  It  is  well  to  make  this  hole 
one  inch  in  diameter  and  allow  the  rats  themselves  to  en- 
large it  so  that  it  will  be  an  actual  "  rat  hole."  Fasten 
securely  a  cage  trap  so  that  all  rats  and  mice  which  enter 
the  barn  must  do  so  through  this  trap.  If  all  doors  and 
windows  are  properly  screened  and  kept  closed  and  all  holes 
are  stopped  up,  this  will  insure  catching  the  first  rat  or 
mouse  that  comes  and  thus  prevent  even  the  beginning  of 
breeding  foci  about  the  premises.^ 

Possibly  enough  expense  is  incurred  annually  in  many 
towns  and  cities  and  enough  effort  expended  to  effectually 
exterminate  rats  and  mice,  but  the  work  is  not  organized. 
A  may  exterminate  the  pests  from  his  place  in  October,  B 
from  his  in  November,  C  from  his  in  April,  and  all  three  of 
their  premises  be  infested  again  for  the  season's  breeding,  the 
work  of  one  driving  the  old  cunning  rats  over  to  neighbors. 
We  have  effective  methods  enough  to  accomplish  the  com- 
plete extermination  with  a  small  part  of  the  effort  and  ex- 
pense wasted  by  our  communities  annually.  What  we  lack  is 
effective  organization.  Rats  and  mice  tend  to  leave  buildings 
in  the  spring  and  migrate  back  to  them  in  the  fall.  Since  our 
experience  with  rats  and  the  plague  in  San  Francisco,  and  in 
view  of  the  fact  that  other  cities  or  even  towns  may  be  called 
upon  at  any  time  to  fight  the  plague,  every  home  ought  to  do 
its  part,  and  every  community  ought  to  be  able  to  extermi- 
nate its  own  rats.    The  disease  to-day  is  widely  distributed, 

1  An  even  more  serviceable  trap  which  will  set  itself  and  thus  catch  a 
continuous  stream  of  animals  may  be  made  by  any  ingenious  boy,  possibly 
in  connection  witli  the  manual-training  work.  If  vermin  are  likely  to  gain 
access  to  the  building  by  other  openings,  it  is  well  to  have  an  entrance  to 
the  trap  inside  the  building  as  well. 


184 


(^IVIC^  BIOLOGY 


and  no  one  can  tell  where  some  migrating  rat  will  carry  it 
next.  Thus  while  other  considerations  of  damage  and  general 
public  health  make  this  Avork  expedient,  danger  from  plague 
renders  it  imperative.  People  who  do  not  know  have  no  right 
to  opinions  in  such  vital  matters,  and  the  time  must  come 
when  the  ignorant  and  negligent  shall  not  continue  to  vitiate 
the  best  civic  efforts  of  our  towns  and  cities.^ 

Cannot  the  biology  class  in  the  high  school  or  local  acad- 
emy, assisted  by  the  boys  of  the  upper  grades,  supply  the 
intelligence  and  generalship,  and  bring  about  the  cooperation 

and  organization  of  the  civic 
effort  to  render  the  work  of 
extermination  effective  — 
even  to  the  last  pair  in  the 
town,  or  the  lirst  pair  that 
migrates  to  it  ?  Might  not 
this  work  alone  go  far 
toward  repaying  to  the  com- 
munity the  cost  of  public 
education  ? 

Mice  should  be  dealt  with  as  thoroughly  as  rats  in  all  these 
campaigns,  and  they  possess  so  little  cunning  that  they  can 
easily  be  extermmated  from  any  premises.  Aside  from  nuisance 
and  damage  caused  by  mice  the  theory  has  been  advanced  that 
germs  of  pneumonia  become  more  virulent  on  passing  through 
the  mouse,  and  thus  cause  severe  and  often  fatal  infections. 


Fiii.  bU.     I'lit^  only  rat  this  trap  cauglit 
A  poor  design  —  wholly  dependent  on  bait 


1  The  thing  to  do,  brothers,  is  to  get  together;  cooperate  with  the  health 
officers ;  lend  them  your  moral  support  as  freely  as  you  have  your  material 
aid ;  and,  above  all,  do  your  part  in  suppressing  the  scoffer,  the  man  who 
laughs  in  his  ignorance,  and  who  in  that  ignorance  wants  to  trifle  with  a 
situation  like  this. 

Remember,  in  these  matters  each  one  of  us  is  in  a  measure  his  brother's 
keeper,  and  let  us  show  this  man  that  if  he  is  not  willing  to  do  his  part,  we 
are  not  only  willing  to  do  ours,  but  we  are  going  to  see  that  he  does  his, 
whether  he  wants  to  or  not.  —  San  Francisco  Report,  1909,  p.  254 


THE  RAT  PROBLEM  185 

Practical  Problems 

The  practical  laboratory  work  of  this  section  shall  consist  in 
actually  exterminating  rats  and  mice  from  your  home  premises. 

Make  a  complete  survey  and  locate  every  rat  hole  in  the 
ground  and  in  the  walls  of  buildings,  and  draw  a  careful 
diagram  with  all  holes  located.  Stop  all  holes  with  earth 
and  mark  on  your  diagram  in  red  ink  all  that  are  reopened. 
Locate  on  your  diagram  also  rooms  or  buildings  of  rat-proof 
construction. 

Make  as  complete  a  collection  of  rat  and  mouse  traps  as  the 
neighborhood  affords.  It  will  be  well  to  have  each  member  of 
the  class  bring  in  all  the  traps  he  has  used  at  the  end  of  this 
campaign,  and  compare  and  discuss  the  merits  and  demerits 
of  different  traps. 

Devise  and  construct  a  better  rat  trap  than  any  used. 

Write  a  brief  statement  of  your  own  experience  in  clearing 
your  home  of  these  pests. 


CHAPTER  XVIII 

FUNGI :  BACTERIA,  YEASTS,  MOLDS,  MILDEWS,  RUSTS, 
SMUTS,  AND  MUSHROOMS 

Although  the  great  mass  of  material  phenomena  elsewhere  had  been 
brought  into  apparent  orderliness  and  system,  here  was  a  region  in  which 
the  unscientific  imagination  rioted  in  mystery  and  extravagance.  The  pene- 
tration of  this  realm  of  obscurity  by  the  discoveries  of  bacteriology  gave 
the  human  race  for  the  first  time  in  its  history  a  rational  theory  of  disease, 
dispelled  the  myths  of  spontaneous  generation,  and  set  the  process  of  decay 
and  kindred  phenomena  in  their  true  relation  to  the  great  cycle  of  living 
and  nonliving  matter. 

The  new  conception  of  the  microscopic  underworld  which  bacteriology 
brought  into  biologic  science  must  be  reckoned  as  a  conspicuous  landmark, 
and,  in  so  far  as  it  has  changed  the  attitude  of  man  toward  the  universe, 
should  be  regarded  as  one  of  the  most  important  triumphs  of  natural 
science. —  Jordan,  "General  Bacteriology,"  p.  23 

The  role  of  fungi  in  the  life  of  the  world.  Saccardo's  "  Syl- 
loge  Fungorum"  has  described  to  date  66,615  species  of  fungi. 
This  means  that  somewhat  more  than  one  fourtli  of  all  the 
plants  known  to  science  belong  in  this  group,  and  over  1000 
new  fungi  are  being  described  each  year.  Food  supply  is  the 
vital  problem  of  plants,  animals,  and  man,  and  in  order  to 
appreciate  the  position  of  the  fungi  in  nature  we  must  study 
the  continual  flow  of  food  material  and  try  to  understand  how 
the  world  is  fed. 

Fungi  lack  chlorophyll ;  hence  they  are  dependent  for  food 
upon  other  plants  and  upon  animals.  Some  tend  to  be  omnivo- 
rous, like  the  common  molds  of  the  household,  and  take  almost 
any  food  that  comes  their  way,  while  others  are  close  feeders, 
living  on  some  one  animal  or  plant  or  even  upon  certain 
organs,  tissues,  or  substances  produced  by  their  necessary 

186 


FUNGI 


187 


host  organisms.  The  great  work  of  fungi  in  nature  is  thus  to 
break  down  organic  matter  and  return  the  elements  to  Mother 
Earth,  that  they  may  be  caught  up  in  the  circle  of  food  supply 
and  live  again.  Without  this  beneficent  work  of  the  fungi 
all  the  animals  and  plants 
that  have  died  since  the 
beginnings  of  life  in  the 
world,  if  they  had  not  been 
eaten  or  burned,  would  still 
cumber  the  earth ;  that  is, 
the  food  of  the  world  would 
be  locked  up  in  dead  forms. 
Burning  returns  the  nitro- 
gen to  the  air, —  a  most 
wasteful  process,  —  while 
the  decay  of  the  dead  bod- 
ies and  waste  matters  of 
animals  and  plants  caused 
by  fungi  holds  this  most 
precious  of  all  foodstuffs 
in  chemical  combination  as 
nitrates,  ready  again  to  be 
built  up  into  the  grains, 
seeds,  fruits,  and  other  food 
products  of  green  plants 
(see  Chapter  IX).  Thus, 
in  burning  wheat  straw  the 
farmer  may  rob  his  land 
of  twenty-five  pounds  of 
nitrogen  in  combination,  worth  |3.75  per  acre  per  year,  and 
an  acre  of  corn  stover  or  cotton  stalks  may  contain  respec- 
tively $7.50  and  $15.30  worth  of  nitrogen.  Where  it  is  cus- 
tomary to  burn  these  materials  is  it  any  wonder  that  the  wheat, 
cotton,  and  corn  fields  are  worn  out? 


NITRATES 


Fig.  90.    Circulation  of  protein  food 
materials  in  nature 

Nitrogenous  food  (protein)  is  the  one  essen- 
tial food  of  both  animals  and  plants.  The 
green  plants  build  up  this  entire  food  sup- 
ply from  the  chemical  elements  by  the 
energy  of  sunlight  working  through  leaf 
green,  or  chlorophyll;  nn  represents  free 
nitrogen  from  the  air,  drawn  into  combi- 
nation by  symbiotic  bacteria  in  the  root 
tubercles  of  clovers,  beans,  etc.  The  non- 
nitrogenous  foods — starches,  sugars,  gums, 
fats,  and  oils  —  are  built  iip  along  with  the 
proteins  and  are  finally  oxidized  to  carbon 
dioxide  and  water,  whether  in  the  animal 
or  plant  body  or  by  rotting  or  burning 


188  CIVIC  BIOLOGY 

Functional  subdivisions,  saprophytic,  parasitic,  and  symbiotic 
fungi.  Saprophytic  fungi  are  those  that  hve  upon  the  dead 
bodies  or  waste  matters  of  animals  or  plants.  Parasitic  fungi 
attack  living  animals  and  plants  and  injure  or  kill  them.  They 
are  the  causative  agents  in  the  larger  part  of  contagious  or 
infectious  animal  and  plant  diseases.  Symbiotic  fungi  live 
with  other  organisms,  to  the  advantage  of  both.  Bacteria  in 
root  tubercles  of  the  legumes  are  familiar  examples.  While 
convenient,  these  lines  of  classification  are  not  hard-and-fast, 
because  it  may  be  difficult,  or  even  impossible,  to  tell  whether 
an  organism,  or  any  part  of  it,  is  really  dead  or  alive.  The 
rough  bark  and  the  heartwood  of  a  living  tree  are  as  dead  as 
they  ever  will  be,-  so  may  be  the  hair  or  cuticle  of  a  living 
animal,  or  the  rind  or  pulp  of  a  ripe  fruit,  or  the  food  material 
of  a  seed  or  egg.  Who  can  say  whether  the  sap  of  a  plant  or 
the  blood  or  milk  of  an  animal  is  dead  or  alive  ?  So  there  are 
all  degrees  of  liveness  or  deadness,  and  a  usually  beneficent 
saprophyte  may  attack  a  half-dead  plant  or  animal,  which  we 
would  call  alive,  but  the  fungus  may  know  better.  Accord- 
ingly we  have  hemiparasitic  and  hemisaprophytie,,  or,  so-called, 
facultative  parasitic  or  saprophytic,  fungi  that  attack  the  living 
or  the  dead  according  to  degrees  of  vitality  or  variations  of 
external  conditions. 

Botanical  position  of  fungi.  All  fungi  are  devoid  of  chloro- 
phyll, but  not  all  plants  that  lack  "  leaf  green  "  are  fungi. 
Dodder  and  the  Indian  pipe  are  flowering  plants  that  have 
adopted  the  parasitic  habit,  and  with  this  degenerate  life  they 
have  lost  the  mechanism  and  the  power  of  making  their  own 
food.  So  we  find  from  a  study  of  their  ways  of  growth  and 
methods  of  reproduction  that  fungi  have  developed  from  the 
alga?.  Flowering  plants  reproduce  by  seeds^  which  are  embryo 
plants  provided  with  food  for  the  start  in  life.  The  ferns, 
mosses,  algae,  and  fungi  reproduce  by  spores,  which,  compared 
with  seeds,  are  almost  inconceivably  small.    Many  seeds  are 


FUNGI  189 

provided  with  hairs  or  wings  to  carry  them  in  winds,  and 
many  float  in  the  water  in  order  to  be  widely  scattered ;  but 
the  spores  of  the  fungi  are  so  light  and  small  that  they  float 
invisible  in  either  air  or  water,  and  so  they  far  outstrip  in  dis- 
tribution the  best  devices  of  the  higher  plants.  As  a  result, 
while  the  flora  of  seed  plants  is  very  different  hi  different 
countries,  the  molds  and  mushrooms,  yeasts  and  bacteria,  are 
more  likely  to  be  the  same  species  the  world  over. 

Compare  seeds  and  spores  as  to  size  and  numbers  pro- 
duced. For  spores  use  the  dust  from  a  patch  of  mold  and 
from  a  puffball,  and  try  to  see,  feel,  smell,  and  taste  tliem. 
The  finger  tips  may  be  black  or  green  with  millions  of  mold 
spores,  but  how  much  can  we  feel  them?  We  can  see  the 
cloud  of  "  smoke  *'  from  a  puffball,  but  as  the  spores  scatter, 
can  we  see  them  in  the  air  (unless  in  a  ray  of  sunlight  in  a 
darkened  room),  and  have  we  ever  tasted  them  iii  food  ? 
Some  people  enjoy  the  tastes  of  certain  molds  and  bacteria  hi 
cheese,  —  Camembert,  Roquefort,  Stilton,  Lim burger,  —  and 
they  may  be  as  wholesome  as  any  other  vegetable.  How  do 
the  different  kinds  smell?  How  many  spores  may  we  be 
breathing  in  with  every  breatli  in  a  musty  room  ?  How  does 
the  number  of  seeds  of  a  grain  plant  or  weed  compare  with 
the  spores  produced  by  a  puffball  ? 

Size  and  power  of  growth.  A  baby  grows  to  double  its 
weight  at  birth  in  five  months.  A  yeast  plant  or  bacterium 
may  double  in  size  in  twenty  or  thirty  minutes.  The  fungus 
thus  has  from  seven  to  ten  thousand  times  the  power  of  growth 
of  the  baby.    Why  this  difference  ? 

Food,  again,  is  the  basis  of  growth.  To  dissolve,  digest, 
absorb,  circulate  to  every  part  of  a  large  body,  assimilate 
(that  is,  build  over  the  foreign  matter  into  the  particular  pro- 
toplasm of  the  species)  are  slow  and  laborious  processes.  Solu- 
tion of  food  substances,  especially  the  proteins  (white  of  egg, 
gluten,  casein,  lean  meat),  is  difficult,  and  absorption  through 


190 


CIVIC  BIOLOGY 


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the  cell  membranes  is  slow.  The  amount  absorbed  is  pro- 
portional to  the  absorbing  surface  exposed  to  the  solution. 
With  these  points  in  mind  we  may  understand  why  the  ac- 
tive mechanisms  in  living  things  are  so  minute,  for  only  in 
this  way  are  they  able  to  present  the  largest  possible  sur- 
face for  both  the  escape  of  waste  matters  and  the  absorption 

of  food.  The  diagram 
on  this  page  presents 
these  relations  in  sim- 
ple form.  A  one-inch 
cube  is  seen  to  have 
six  square  inches  of  ab- 
sorbing surface,  while 
in  a  ten-inch  cube  each 
cubic  inch  has  only  six 
tenths  of  one  square 
inch  of  surface.  The 
rate  of  absorption  be- 
ing the  same,  the 
smaller  cube  could 
absorb  ten  times  as 
fast  as  a  similar  bulk 
of  the  larger  cube.  So 
we  see  why  the  small- 
est organisms  may  be 
the  most  efficient  in  ab 
sorbing  food  and  have 
the  greatest  power  of 
growth.  It  is  estimated  that  a  bacterium  jq^q^  of  a  milli- 
meter in  diameter,  which  can  double  in  size  in  twenty  min- 
utes, given  food  and  suitable  conditions,  might  grow  to  a 
mass  the  size  of  the  earth  in  about  five  days.  A  yeast  plant, 
which  is  much  larger  but  which  can  double  in  thirty  minutes, 
might  grow  to  a  similar  mass  in   about  two  weeks.     How 


Fig.  91.  Diagram  to  show  relation  of  surface 
to  bulk  in  large  and  small  organisms 

The  law  is:  Bulk  increases  as  the  cube,  while 
surface  for  absorption  increases  only  as  the 
square.  Since  bulk  so  rapidly  outstrips  surface, 
this  relation  tends  to  limit  the  size  of  organisms, 
and  suggests  one  of  the  fundamental  reasons 
why  minute  organisms  possess  such  phenom- 
^enal  powers  of  growth  and  reproduction 


FUNGI 


191 


long  would  it  take  a  pair  of  elephants  to  multiply  to  a  mass 
of  the  same  weight  ? 

Size.  As  we  have  seen,  mere  size  counts  for  little.  Bac- 
teria, the  smallest  plants  known,  are  infinitely  more  powerful 
than  sequoias  or  whales.  Fungi  range  in  size  from  the  giant 
puff  ball  (the  fruiting  body  of  which  may  grow  to  three  or  even 
four  feet  in  diameter)  to  microscopic  bacteria,  and  some  of 
these  are  quite  possibly  too  minute  to  be  visible  under  our 
best  microscopes.  In  the  fruiting  portion  of  a  large  mushroom 
we  see  but  a  small  part  of  the  whole  fungus.  This  consists,  as 
we  shall  see  later,  of  a  feltwork  of  microscopic  threads  (the 


A  ^^  B 

Fig.  92.    Size  of  microscopic  fungi 

Comparative  size  of :  A,  a,  molds ;  h  and  c,  yeasts ;  d,  bacteria  equally  magnified  ; 

B,  e,  minute  particle  of  dust ;  /,  point  of  finest  cambric  needle ;  g,  bacteria  under 

less  magnification.   After  Conn 

feeding,  or  vegetative,  portion),  which  permeate  the  soil,  leaf 
mold,  wood  of  a  tree,  or  other  substance  in  which  the  plant  is 
growing,  possibly  for  many  feet  in  every  direction. 

Yeasts  {Saccharomycetes,  the  sugar  fungi —  saccharon,  "sugar " ; 
myces,  "fungus").  Yeasts  are  the  "sweet  tooth"  fungi,  and 
their  work  in  nature  is  to  break  down  sugars  by  the  process 
known  2^'^  fermentation.  The  end  products  are  alcohol,  carbon 
dioxide,  and  various  oils  and  flavors  characteristic  of  different 
species  of  yeast.  The  process  of  fermentation  is  represented 
by  the  following  simple  chemical  equation : 

2C0„ 


Sugar 


2C,H,0 , 

Alcohol        Carbon  Dioxide 


Size  and  color.    Common  yeast  plants  are  spherical  or  ellip- 
soidal bodies  about  g^^Q  of  an  inch  in  diameter;  a  cake  of 


192 


CIVIC  BIOLOGY 


compressed  yeast  contains  approximately  10,000,000,000  of 
them.  In  order,  once  for  all,  to  gain  a  notion  of  the  minuteness 
of  microorganisms,  perform  the  following  simple  experiment : 

Sharpen  tlie  point  of  a  teasing-needle  to  a  tine  knife  blade ;  take  a 
bit  of  moist  compressed  yeast,  the  size  of  a  large  pinhead,  on  a  piece  of 
clean,  polished  glass  (a  microscope  slide)  and  cut  the  lump  in  halves. 
Throw  away  one  half  and  repeat  the  operation  and  continue  as  long  as 
you  can  see  to  divide  the  particle.  At  the  last  division  carefully  plant 
one  half  in  a  vial  half  full  of  filtered,  boiled  molasses  and  water  (a  table- 
spoonful  of  molasses  in  half  a  pint  of  potato  water  makes  a  good  cul- 
ture fluid),  to  watch  it  grow  from  day  to  day.  Then,  with  the  point  of 
a  clean  needle,  on  a  perfectly  clean  part  of  the  glass,  cover  the  other  half 

with  a  minute  droplet  of 
water.  Cover  with  a  per- 
fectly clean  cover  glass 
ajid  try  to  count  the  tor- 
ulaB  (yeast  plants)  in  the 
speck  that  you  can  just 
see  with  the  naked  eve. 


Fig.  93.   Yeast  plants,  highly  magnified,  show 
ing  successive  stages  of  growth  by  budding 

After  Conn 


In  color  most  of  the 
common  yeasts,  when 
seen  in  mass,  are  whit- 
ish or  slightly  yellowish  gray,  the  color  of  a  fresh  yeast  cake, 
but  a  few  species  are  pink,  red,  or  black. 

Distribution.  Yeasts  are  everywhere ;  so  the  question  is 
not.  Where  shall  we  go  to  find  them,  but.  Where  go  to  escape 
them  ?  We  eat  them  by  billions,  baked,  in  our  daily  bread ; 
Ave  drink  them  by  millions,  alive,  in  our  cider,  beer,  or  wine ; 
we  breathe  them  in,  alive,  with  every  breath,  and  drhdv  them, 
alive  or  dead,  according  as  the  Avater  is  raw  or  boiled,  with 
every  drink  of  water  we  take ;  they  are  all  over  us  all  the 
time,  in  our  hair,  on  our  skins,  in  all  our  clothes,  and  we 
cannot  possibly  l)eat  them  out,  brush  them  off,  or  even  wash 
them  away  —  the  harmless,  useful,  patient,  persistent,  omni- 
present little  sugar-hunting  yeast  plants.     We   might   suck 


EUNGI 


193 


most  of  them  out  of  our  carpets  aud  homes  with  a  vacuum 
cleaner,  but  this  would  not  be  worth  our  while  if  it  were 
not  for  the  fact  that  they  are  associated  in  the  dust  with  less 
reputable  bacteria. 

There  is  just  one  point  that  we  should  learn  in  a  way  Ave 
can  never  forget.    The  skins  of  fruits,  of  course,  are  covered 


Fig.  94.    Experimeiit.s  in  growing  yeast. 

1,  yeast  planted  in  molasses  1  part,  water  5  imrts,  kept  at  room  temperature; 

2,  same,  kept  in  dark;  3,  planted  in  filtered,  boiled,  or  distilled  water;  4,  same 

as  1,  not  planted  :  T),  same  as  1,  kept  in  cracked  ice 

with  yeasts  and  with  spores  of  molds.  This  fact  is  related  to 
one  of  the  large  industries  of  the  world  —  the  picking,  hand- 
ling, and  marketing  of  fruits. 

Experiment  1.  Have  the  class  collect  a  number  of  the  fruits  avail- 
able at  the  season.  Scrape  the  surface  lightly  with  a  sharp,  clean  scalpel 
point  or  knife-needle  (or  wash  with  a  fine  brush  into  a  drop  of  water  on 


194  CIVIC  BIOLOGY 

a  slide).  Mount  scrapings  in  a  small  droplet  of  water  and  examine 
under  a  microscope.  Be  particular  to  scrape  especially  in  the  little  crack 
around  the  stem.  Can  you  see  from  results  why  stems  should  not  be 
pulled  out  in  picking  fruit  ? 

Experiment  2.  Pull  out  the  stems  and  make  slight  punctures  and 
scratches  through  the  skins  of  a  number  of  apples  or  pears,  set  them 
aside  with  an  equal  number  of  perfectly  sound  fruits,  and  examine  from 
time  to  time  for  signs  of  decay. 

Experiment  3.  Plant  scrapings  from  the  skins  of  the  various  fruits 
in  vials  of  dilute  fruit  juice  (filtered  cider,  the  juice  from  canned  fruit, 
diluted  with  half  water  if  too  sweet),  plug  with  cotton,  and  examine 
later  for  growth  of  yeasts  and  molds. 

If  microscopes  are  not  at  hand.  Experiments  2  and  3  can  be  done 
perfectly  well  without  them.  What  do  these  experiments  mean  with 
reference  to  honest  hand  picking  and  packing  of  fruits  ?  If  one  decayed 
fruit  wets  or  touches  another,  what  is  likely  to  happen?   Contagion? 

Uses.  In  making  bread  we  use  the  carbonic  acid  which  the 
yeast  plants  give  off  to  form  bubbles  in  the  dough.  These 
bubbles  are  hardened  in  baking,  the  alcohol  is  driven  off,  and 
the  bread  remains  light.  In  making  alcohol  we  use  the  sugar 
of  fruits  or  the  starch  of  potatoes,  barley,  corn,  rye,  which 
has  been  changed  to  sugars  by  digestive  ferments;  then  either 
the  wild  yeasts  that  were  on  the  fruits  or  the  pure-culture 
yeasts  that  we  add  to  the  fruit  juice  mash  or  wort  ferment 
the  sugars,  and  the  alcohol  may  be  distilled  off  by  heat. 

If  the  yeast  fermentation  has  been  too  slow,  or  if  the  mate- 
rial is  allowed  to  stand  after  alcoholic  fermentation  is  complete, 
other  microorganisms,  with  which  yeast  is  always  associated, 
begin  to  turn  the  alcohol  into  acetic  acid,  and  we  have  sour 
bread,  sour  beer,  and  vinegar.  This  process  may  be  roughly 
represented  by  the  equation 

Alcohol    Oxygen     Acetic  acid        Water 

Then  if  vinegar  is  exposed  to  the  air,  another  organism  may 
change  the  acetic  acid  further  into  carbonic  acid  and  water, 
and  the  decomposition  of  the  starch  or  sugar  is  complete. 


FUNGI 


195 


Experiment.  To  a  quart  of  warm  potato  water,  not  filtered,  add  a 
half  pint  of  molasses  and  a  yeast  cake,  previously  mixed  to  a  smooth 
cream  in  a  gill  of  fresh  milk.  Keep  in  a  dark  place  at  between  75°  and 
90°  F.,  and  observe  from  time  to  time.  When  bubbles  are  rising  rapidly, 
conduct  the  gas  into  a  vial  of 
lime  water,  as  shown  in  Fig.  95, 
noting  that  the  same  change 
takes  place  that  occurs  when  we 
expire  into  limewater : 

CaO  +  CO2  =  CaCOg 

Liine      Carbon      Chalk  or 
dioxide    limestone 

Test  the  liquid  by  odor  and 
especially  by  taste.  As  soon  as 
fermentation  is  complete  (that 
is,  when  the  sweet  taste  has  dis- 
appeared), pour  out  half  a  pint 
into  a  flat  dish  and  set  in  a  warm 
place,  protected  from  dust,  to 
study  the  formation  of  vinegar. 
With  the  remainder  attach  the 
flask  to  a  small  still,  heat  care- 
fully, and  test  the  first  gill  for 
alcohol  by  taste,  smell,  and  by 
burning. 

In  doing  this  experiment  dif- 
ferent members  of  the  class,  or 

different  class  groups,  may  use  different  materials  —  fruit  juices,  potato, 
corn  or  rye  mashes,  malt  decoction  —  and  thus  add  to  the  interest. 

Pure  cultures.     Before    reading  the   next   experiment  try 
hard  to  think  how  you  would  make  a  pure  culture  of  a  plant 

3  o'o^o"  ^^  ^^  ^^^^  ^^  "g^oioo"  ^^  ^^  ^^^^  ^^  diameter.  Let  each 
member  of  the  class  write  out  his  method  and  then  compare 
^is  result  with  those  of  the  rest  of  the  class.  This  is  a  test 
and  measure  of  power  to  think,  imagine,  and  reason.  When 
Louis  Pasteur  first  thought  this  out,  he  marked  the  greatest 
epoch  in  control  of  disease  that  history  records.  Pasteur  did 
this  first  with  the  yeast  plant  in   1856.     Up  to   this   time 


Fig.  95.   Testing  the  gas  from  yeast, 
fermentation  with  limewater 


196 


CIVIC  BIOLOGY 


fermentation  was  supposed  to  be  a  purely  chemical  process, 
and  accordingly  brewers  and  vintners  had  employed  chemists 
to  try  to  relieve  them  from  the  great  losses  caused  by  diseases 
of  wine  and  beer.  We  now  know  that  these  were  caused  by 
wild  yeasts  and  otlier  microorganisms,  and  the  problem  is  a 
logically  simple  one  of  weeding  them  out  of  the  cultures. 
The  first  requisite  is  to  isolate  and  study  the  different  organ- 
isms involved,  in  pure  cultures,  and  this  is  equally  true  of  any 
germ  disease  of  plants,  animals,  or  men. 

Experiment  1.  First  necessary  step:  Get  the  yeast  plants  single; 
that  is,  make  a  uniform  suspension  in  water.  To  do  this  make  a  dilute, 

well-rubbed-up  suspension 
in  a  slender  test  tube  or 
straight  vial,  and  force 
down  through  this  a  tight, 
hard  plug  of  sterilized  ab- 
sorbent cotton.  The  liquid 
above  the  cotton  will  be 
pretty  sure  to  contain  noth- 
ing but  single  yeast  plants. 
Experiment  2.  Second 
step :  Get  the  single  plants 
far  enough  apart  so  that  we  can  work  with  them ;  that  is,  dilute  the 
suspension.  Add  a  drop  to,  say,  one  quart  of  boiled,  filtered  water,  and 
shake  thoroughly.  (If  too  many  plants  are  still  present,  we  may  have  Uy 
repeat  the  dilution.) 

Experiment  8.  Third  step:  Plant  a  drop  or  a  few  drops  (according 
to  the  dilution)  in  some  medium  solid  enough  to  keep  them  from  flow- 
ing together  and  getting  mixed  up,  and  clear  enough  so  that  we  can  see 
them  after  each  one  has  grown  sufficiently  to  forui  a  visible  colony. 
Starch  jelly  made  with  sweetened  water  (or  potato  water  filtered) 
makes  a  good  mediuui  foe  yeasts  and  molds.  Stir  the  drop  of  sus- 
pension thoroughly  into  a  tablespoonful  of  the  jelly  as  soon  as  it  is 
cool  enough  not  to  injure  the  yeast  (when  it  feels  neither  cool  nor 
warm  to  the  hand),  and  pour  in  a  thin  layer  into  a  Petri  dish  (or  on 
a  clean  piece  of  glass  which  can  be  covered  securely  from  the  dust). 
Keep  in  a  warm  place  away  from  the  light,  and  in  a  day  or  two  whitish 
specks  begin  to  appear,  if  the  work  has  been  carefully  done,  scattered 


Fig.  96.   A  lifter,  cut  from  tin,  or,  better, 
from  thin  sheet  aluminium 

It  is  sterilized  by  holding  the  end  in  a  flame  for 
an  instant,  giving  it  only  time  to  cool  befoi'c 
using,   a,  sheet  of  metal  indicating  how  the  lift- 
ers are  cut.    (One  half  natural  size) 


FUNGI  197 

evenly  through  the  mass.  If  a  speck  is  spherical  and  clearly  distinct 
from  all  others,  we  may  pick  it  out  with  a  sterilized  lifter  and  be 
reasonably  sure  that  we  have  yeast  plants  all  descended  from  a  single 
parent  plant  —  that  is,  a  pure  culture. 

Diseases  caused  by  yeasts.  Quite  naturally  one  species  of 
yeast  causes  blight  of  sorghum,  and  another,  a  disease  of  the 
crocus,  and  one  or  two  others  attack  animals  and  man. 

Molds  and  mildews.  These  are  the  most  troublesome  fungi 
of  the  household.  They  take  everything  in  the  way  of  food 
or  clothing,  carpets,  linen,  and  even  books,  that  they  can  get 
their  spores  on,  if  conditions,  especially  of  moisture,  .favor 
their  growth;  and  since  they  always  can  get  their  spores  on 
everything  that  tlie  air  touches,  it  behooves  the  home-keeper 
to  see  to  it  that  nothing  of  value  is  left  where  dampness,  air 
stagnation,  and  darkness  may  permit  growth  of  these  little 
robber  plants.  Conn's  statement  is :  "  If  the  air  of  a  room 
becomes  damp  or  '  close,'  as  we  say,  it  is  almost  certain  that 
molds  will  begin  to  grow  upon  any  organic  substance."  While 
in  common  household  parlance  molds  and  mildews  are  sup- 
posed to  be  distinct,  the  microscope  reveals  them  as  identical, 
the  only  difference  being  that  they  grow  less  luxuriantly  on 
leather,  cloth,  and  paper  than  they  do  on  richer  and  moister 
foods. 

Botanical  position  and  structure.  The  word  "mold"  is 
merely  a  popular  designation  for  a  variety  of  different  kinds 
of  plants.  The  term  has  no  botanical  standing,  but  is  so 
firmly  fixed  in  common  usage  that  we  cannot  improve  upon 
it  to  designate  the  somewhat  similar  felt-like  growth  that 
is  likely  to  cover  everything  damp.*  This  growth  is  tech- 
nically known  as  the  mycelium  of  a  fungus,  and  when  we 
examine  it  we  find  the  key  to  understanding  the  growth  and 
structure  of  all  the  higher  fungi,  molds,  and  mushrooms  — 
that  is,  those  above  the  bacteria  and  yeasts,  and  some  of  these 
form  similar  mycelia.     The  single  element  is  a  microscopic 


198 


CIVIC  BIOLOGY 


thread,  the  hypha,  which  in  some  fungi  is  tubular  and  in 
others  is  septate,  that  is,  composed  of  cells  end-to-end.  Hyphee 
branch  continually  and  seek  the  cracks  and  minutest  pores, 
and  so  are  able  to  burrow  and  digest  their  way  into  all  sorts 
of  apparently  solid  substances.  The  hyphse  are  functionally 
of  two  kinds  :  first,  the  threads  that  burrow  and  feed  in  or  on 


Fig.  97.   Two  common  molds  in  different  stages  of  growth 

A,  B,  C,  a  common  blue  mold,  Penlcillium ;  A,  spores  germinating;  B,  as  seen 

growing  in  vial  of  liquid ;   C,  aerial  (or  fruiting)  hyphte  more  highly  magnified ; 

D,  E,  F,  similar  stages  in  the  growth  of  a  black  mold,  Rhizopus 

the  food  material  —  the  vegetative  hyph?e ;  and,  second,  the 
fruiting  hyphse,  which  grow  out  of  the  mass  into  the  air  (or 
water  in  case  of  the  water  molds)  to  form  the  various  kmds 
of  spore-bearing  organs.  These  ideas  are  fundamental  to 
control  of  fungi,  and  we  should  be  sure  that  they  are  entkely 
clear  in  working  out  the  following  experiments.  As  we  aim  to 
destroy  weeds  before  they  go  to  seed,  so  we  must  adopt  meth- 
ods to  prevent  our  fungus  enemies  from  ripening  their  spores. 


FUNGI  199 

Observations  and  experiments.  1.  For  at  least  one  hour  in  preparation 
of  this  lesson  have  each  member  of  the  class  hunt  over  his  home 
premises  and  collect  specimens  of  everything  he  can  find  that  appears 
to  be  moldy.  Compare  these,  to  try  to  see  how  many  different  molds 
we  have.  The  mycelium  of  nearly  all  molds  and  mushrooms  is  white, 
but  the  spores  and  sporing  organs  may  be  any  color  —  white,  red, 
green,  gray,  brown,  or  black.  Note  particularly  the  kinds  of  places  in 
which  molds  are  found  growing  best,  with  especial  reference  to  damp- 
ness, lack  of  light  and  direct  sunshine,  and  lack  of  ventilation. 

2.  Select  tyi3ical  specimens  and  arrange  in  jelly  tumblers  (or  even  in 
straight-necked  vials)  for  further  study.    Keep  covered  when  not  in  use. 

3.  Make  a  series  of  mold  gardens  in  small  vials,  trying  to  have  as 
pure  cultures  as  possible.  Use  all  sorts  of  materials  —  foods  and  even 
linen  and  cotton  cloth.  Plant  spores  from  No.  2  by  touching  a  patch 
of  mold  with  the  point  of  a  needle  and  then  touching  it  to  a  single 
point  in  the  material  in  the  vial.  Watch  it  grow  from  day  to  day, 
noting  particularly  how  long  it  takes  to  begin  to  produce  spores.  To 
insure  dampness  the  vials  should  be  covered  or  corked  tightly  (heavy 
tinfoil  pressed  over  the  mouth  of  the  vial  makes  a  convenient  cover), 
and  should  contain  a  little  water.  The  material  may  be  held  out  of 
the  water  on  a  bit  of  glass.' 

Stand  some  of  the  vials  in  bright  sunlight,  and  keep  the  rest  in  the 
dark,  noting  differences  in  growth.  Keep  some  on  ice  (cold  storage) 
and  compare.  Keep  some  protected  from  dust  in  a  dry  air,  not  covered 
tightly,  and  note  influence  of  dryness  on  growth  of  molds. 

In  order  to  see  the  growth  clearly,  make  a  series  of  mold  gardens  ^  in 
a  perfectly  transparent  liquid  medium.  Fruit  juice,  diluted  with  one 
half  water,  filtered,  serves  the  purpose  well.  Plant  spores  from  the 
different  molds  on  the  surface,  study  from  day  to  day,  make  careful 
drawings,  and  note  especially  the  time  required  for  spores  to  begin 
to  form. 

4.  Sketch  a  plan  by  which  you  would  keep  a  home  as  free  as  possible 
from  molds. 

1  Hodge,  "Nature  Study  and  Life,"  p.  4-57 ff.,  describes  and  figures 
mold  gardens. 


CHAPTER  XIX 

FUNGI  CONTINUED :    MUSHROOMS,  POISONOUS 
AND  EDIBLE 

To  know  several  different  kinds  of  edible  mushrooms,  which  occur  in 
greater  or  less  quantity  through  the  different  seasons,  would  enable  those  in- 
terested in  these  plants  to  provide  a  palatable  food  at  the  expense  only  of  the 
time  required  to  collect  tliem.  To  know  several  of  the  poisonous  ones  also  is 
important,  in  order  certainly  to  avoid  them. — Atkinson,  ''  Mushrooms," p. iv 

General.  Persistent  search  extending  through  a  series  of 
years  in  any  favorable  locality  would  reveal  the  presence  of 
about  1000  species  of  these  our  largest  and  most  conspicuous 
fungi.  In  one  season  one  might  expect  to  find  from  200  to 
400  species.  Of  the  entire  number,  according  to  Mcllvane, 
nine  species  (all  amanitas)  are  deadly  poisonous,  about  a 
dozen  contain  minor  poisons,  and  are  rated  as  suspicious  or 
dangerous,  735  are  edible,  while  the  rest  have  either  not  been 
tested  or,  on  account  of  woodiness,  disagreeable  taste,  small 
size,  or  extreme  rareness,  are  of  interest  only  to  the  specialist. 

Form  and  structure.  Mushrooms,  like  other  fungi,  are  active 
in  causing  decay,  chiefly  in  waste  matters  of  plants  and  ani- 
mals, but  a  number  attack  the  roots  and  wood  of  trees,  and, 
naturally  timber  and  wooden  structures. 

From  our  knowledge  of  the  molds  it  is  an  easy  step  to  the 
life  history  of  a  mushroom.  Both  organisms  begin  as  spores ; 
in  both,  these  sprout  and  grow  to  form  a  mass  of  food-absorb- 
ing mycelium.  In  mushrooms  this  may  extend  many  feet  in 
the  soil,  in  leaf  mold,  or  in  the  wood  of  a  tree.  In  both,  some 
of  the  mycelial  threads  finally  grow  out  of  the  food  substance 
and  complete  the  life  cycle  by  producing  the  spores  with  which 

200 


FUXGI 


201 


we  started.  The  conspicuous  part  of  a  mushroom  is 'thus  a 
small  fraction  of  the  entire  plant  —  the  spore-bearing  organ, 
or  sporophore. 

Combme  the  collecting  of  mushrooms  with  the  field  work 
with  birds,  insects,  and  trees  in  the  early  fall.  In  fact,  this 
is  the  most  favorable  part  of  the  school  year  for  all  forms 
except  the  morels,  whose  season  is  May  or  June.    Preserve 


Fig.  98.    Growth  stages  of  a  mushroom 

A,  mycelium  with  forming  buttons,  drawn  from  Agaricus  canipestrls.  The  other 
figures  are  from  Amanita  phalloides  (the  deadly  amanita)  and  show :  B,  a  button 
bursting  the  volva  (or  sac)  ;  C,  the  same  in  longitudinal  section ;  and  D,  a  mush- 
I'oom  showing  a,  the  pileus  (or  cap),  6,  the  velum  (or  veil),  which  has  torn  from 
the  margin  of  the  cap  and  remains  as  a  ring  around  the  stem,  and  c,  the  remains 
of  the  volva,  which  forms  a  cup 

the  mushrooms  collected  for  winter  study  by  drying ;  even 
many  of  the  softer  ones  may  be  preserved  in  this  way  if  they 
are  dried^in  a  current  of  hot  air. 

Amanitas.  Before  collecting  mushrooms,  fix  clearly  in  mind 
the  characters  of  the  deadly  genus  Ammiita. 

Other  varieties  of  fungi  may  interfere  with  digestion,  but  to  the 
Amanitas  all  deaths  from  toadstool  poisoning  are  traceable.  Its  subtile 
alkaloid  is  absorbed  by  the  system,  and  in  most  cases  lies  unsuspected 


20-2  CIVIC  BIOLOGY 

for  from  six  to  twelve  hours,  then  its  iron  grip  holds  to  the  death.   For 
centuries  it  has  defied  all  remedies.  —  McIlvane,  p.  5 

The  amaiiitas  are  the  most  conspicuous,  beautiful,  and,  too 
often,  the  most  abundant  mushrooms  to  be  found  in  the  woods 
from  frost  to  frost.  Of  the  twenty-eight  species  nine  are 
deadly,  ten  are  doubtful,  and  nine  are  considered  edible. 

The  three  characters  which  infallibly  mark  an  amanita  are 
white  spores,  a  ring,  and  a  volva,  or  cup.  In  order  to  understand 
these  terms  and  others  that  we  need  to  know,  study  an  amanita 
as  a  type.  Fig.  98  shows  all  the  constituent  parts  and  all  the 
characteristic  stages  of  growth  of  Amayiita  phalloides. 

The  parts  in  order  of  growth  and  formation  are 

Mycelium  :  extremely  fine  white  threads,  uniting  here  and  thereto 
form  larger  strands  —  the  nutritive,  or  vegetative,  part  of  the 
fungus. 

Buttons  :  white  knots  or  balls  in  the  mycelium,  the  beginnings  of 
spore-forming  bodies  (mushrooms).  One  button  cut  lengthwise 
shows  the  parts,  which  will  be  more  clearly  differentiated  later 
on.  Note  especially  that  the  mushroom  proper  at  this  stage  is 
completely  enveloped  in  a  sac.    Not  all  mushrooms  have  this  sac. 

Sporophore,  consisting  of 

1.  Stem:  the  part  which  springs  directly  out  of  the  mycelium 

and  supports  the  pileus. 

2.  Pileus^  or  Cap  :  the  umbrella-shaped  part  which  carries,  on  its 

under  surface,  radiating,  leaf-like  structures  —  the  gills. 

3.  Gills :  the  organs  from  the  surfaces  of  which  the  spores  are  set 

free.    The  shape  that  the  spore-forming  surface  assumes  is  a 

prime  character  in  classification.    It  is  produced  into  gills  in 

the  Affaricacece,  into  spines  in  the  Hydnacece,  into  tubes  in 

the  Boleti,  and  into  fine  pores  in  the  Polypori. 

Spores  ;  Place  a  cap  from  which  the  stem  has  been  removed,  gills 

down,  on  a  piece  of  white  or  black  paper,  and  cover  tightly  with 

a  tumbler  or  bell  jar.    Leave  for  an  hour  or  so,  and  examine  the 

spore  print  and,  if  a  microscope  is  available,  the  spores. 

VoLVA,  or  Sac  :  the  membranous  sac  which  may  envelop  the  entire 

sporophore  in  the  button  stage  ;    also  applied  to  the  portion 

which,  after  rupture,  remains  as  the  cup  at  the  base  of  the  stem. 


FUNGI  203 

Warts  :  irregular  flecks,  or  patches,  on  the  surface  of  the  cap,  formed 
if  the  volva  ruptures  about  the  equator  and  the  upper  portion  is 
carried  up  and  remains  adherent  to  the  growing  pileus  (not 
the  case  with  Amanita  phalloides). 

Velum,  or  Veil  :  a  membrane  which,  in  some  forms,  attaches  the 
margin  of  the  pileus  to  the  stem.  When,  in  growing,  the  cap 
tears  away  from  the  velum  around  its  margin,  the  velum  re- 
mains attached  to  the  stem  as  the  annulus,  or  ring. 

The  presence  of  the  three  characters,  white  spores,  ring,  and  cup 
(which  may  be  reduced  to  a  scaly,  bulbous  base  to  the  stem), 
mark  the  specimen  as  an  amanita.  In  collecting,  why  should 
we  be  sure  to  have  the  base  of  the  stem  complete?  Why  should 
we  never  mix  buttons  with  edible  mushrooms  ? 

Classification.  Sort  the  mushrooms  collected,  using  the 
outline  given  below.  If  you  place  the  dried  specimens  in  a 
jar  packed  with  wet  paper  the  day  before  beginning  the  work, 
many  of  them  will  absorb  moisture  and  become  approximately 
like  fresh  specimens : 

1.  All  forms  with  gills  underneath  the  pileus  may  or  may  not  have 
stems  — Agaricacece. 

2.  Hedgehog  mushrooms  :  forms  whose  spore-forming  surface  is  pro- 
duced into  spines  which  hang  downward.  They  may  be  umbrella-shaped 
or  irregularly  tuberculate  or  branched  —  Hydnacece. 

3.  Mushrooms  with  a  honeycomb  structure  of  tubes  in  place  of  gills ; 
soft  and  with  the  tubes  readily  separable  from  the  cap  —  BoletL 

4.  Fungi  with  fine  pores  underneath  the  pileus.  Many  species  become 
corky  or  woody,  the  bracket  fungi  of  the  woods  —  Polypori. 

5.  Coral  mushrooms  :  may  be  simple,  erect  clubs  or  large,  branching 
masses,  the  branches  being  erect.  The  spores  are  produced  over  most  of 
the  exposed  surface  —  Clavariacece. 

6.  The  morels  and  cup  fungi.  Some  of  these  have  stem  and  cap,  but 
produce  the^^ores  in  pits  or  irregular  depressions  on  the  outer  surface 
of  the  conical  or  cylindrical  cap.  Other  forms  are  cup-shaped  or  saucer- 
shaped  —  Discomycetes. 

7.  Puffballs  and  earthstars  :  mushrooms  in  which  the  spores  are  pro- 
duced within  a  closed  cavity,  which  may  open  by  an  apical  pore  or  by 
the  irregular  breaking  of  the  wall  (peridium)  —  LycoperdacecE. 


204  CIVIC  BIOLOOY 

8.  Stinkhorns,  mushrooms  which,  once  smelled,  can  never  be  mistaken 
for  anything  else  or  forgotten.  The  immature  plants,  known  appropri- 
ately as  witches'-eggs,  resemble  puffballs  externally ;  but  as  one  matures, 
out  shoots  a  long,  hollow  stem  bearing  pendent  from  the  tip  a  small 
j)ileus,  and  this  carries  the  spores  in  reticulations  of  its  outer  surface  — 
Phalloidect. 

9.  Trembling  mushrooms  :  soft,  gelatinous  fungi  (witches'-butter)  in. 
color  varying  from  white  to  orange,  red,  or  brown,  generally  found  grow- 
ing on  wood  or  parasitic  on  other  fungi  —  Tremellacefv.. 

The  first  purpose  of  these  lessons  should  be  to  learn  to 
recognize  the  deadly  genus  Amanita.  Then  let  each  student 
acquaint  himself  with  as  many  as  possible  of  the  abundant 
edible  mushrooms.  An  excellent  plan  is  to  have  the  class 
unite  in  making  a  neat  card  catalogue  of  the  most  abundant 
and  valuable  mushrooms  found  growing  in  the  locality — this 
catalogue  to  be  left  in  the  laboratory  as  part  of  its  biological 
equipment  during  the  year.  A  sample  card  might  read  about 
as  follows : 

ORDER:  AGAlilCACE^ 

Genus  :  Lactarhis         Spkciks  :  (leliciosus         Spohks  :  White 

Delicious  Milky  Mushroom 

Edible,  excellent  (first  taste  a  little  acrid) 


Space  for 
Color  Picture 


3-10  cm.  high  ;  5-13  cm.  broad ;  funnel-shaped. 

Color :  orange,  in  concentric  darker  and  lighter 
zones  around  cap ;  becomes  lighter,  often  green^ 
ish,  with  Bjge. 

Gills :  decurrent,  saffron  yellow.  Milk  at  first  reddish 
orange,  quickly  turning  to  dull  greenish  —  char- 
acteristic of  every  part  of  plant  when  bruised. 

Odor:  aromatic. 

Taste  :  delicious. 

Habitat :  damp  coniferous  woods. 

Season  :  July  to  October. 
Notes :  Have  found  it  abundant  since  our  first  field  work  —  Sejv 
tember  10  up  to  October  23. 


FUNGI 


205 


Table  of  Gkneka  of  Agaricace.e  (Gill-bearing  Mushrooms)^ 

I'lLKfS  DISTINCT  FROM  FLESHY  STEM 


SrouES 

Leucospob.ic 
(White) 

RnoDospoRx 
(Pink) 

OciinospoRjF. 
(Yellow-brown) 

Porpiiyrosporm: 
(Purple-brown) 

ME[.AKO!IPOR.f: 

(Black) 

Ring  and  volva 

Amanita^ 

Volva,  no  ring 

Anianitopsis* 

Volraria^ 

Acetabulana 

Chitonia 

Ring,  no  volva 

Lepiota* 

Agaricua  * 

CoprinuH  * 

No  ring 

Piute  us 

Bolbitius 

Pilosace 

PI  LEI  S  CONTINUOUS  WITH  FLESHY  .STEM 


King 

Armillaria  * 

Pholiota* 
C'ortiuarius* 

Stropharia^ 

Gomphidius 

Sinuate  gills 

Tricholorna  * 

Entnloma^ 

Hebeloma  ' 

Hypholoma* 

Panseolus  3 

LactaHus^ 
(milky) 

liussula* 
(brittle) 

Inocybe 

Anellaria 

Gills  often  decnr- 
rent 

Cantharellus  * 

Xerotus 

Nyctalis 

Clitoj/ilus* 

Flammula 
Paxillus* 

Growing  on  wood. 
Stem  usually  ec- 
centric, lateral ,  or 
wanting 

Lcnzites 
Lentinus     ' 
Pleurotus  * 

(fleshy) 
Panus 

(leathery) 
Trogia 

(gills  crisped) 
SchizQphyllmii^ 

Claudopns 

Crepidotus 

PILEUS  DISTINCT  KKOM  CARTILAGINOUS  STEM 


Margin  of  pileus 

inroUed  in  young 

plant 

Collybia^ 

Leptonia 

Xaucoria 

Psilocybe* 

Marasmius* 
Heliomyces 

Margin  of  pileus 

straight  in  young 

plant 

Mycena 
Hiatula 

Nnlanea 

Pluteolus 
Galeru 

Psathyra 

Psalhyrella 

Gills     decurrent, 

pileus  usually  um- 

bilicate 

Omphalia           \  Krcilia 

Tubaria 

Deconica 

Montagnites 

1  Arranged  by  Theodate  L.  Smith,  Ph. I). 

^  Contains  deadly  poison  species.    No  species  of  Amanita  should  be  eaten 
without  Mentijication  by  an  expert. 

*  Contains  suspicious  species  or  tliose  having  minor  poisons. 

*  Contains  edible  species  and  none  known  to  be  poisonous  except  those 
given  below  : 

Lepiota  morganl  has  green  spores ;  it  is  one  of  the  finest  edihles,  but  makes 

ill  about  one  person  in  six. 
Russula  emetica  causes  nausea  in  some  people,  but  is  harmless  for  others. 
Tricholorna  sulphure\is  smells  like  illuminating  gas  and  is  reputed  poisonous. 
Hygrophorus  conictis  is  reputed  poisonous. 
Clitocyhe  illudens  smells  and  tastes  like  soap  and  is  reputed  poisonous. 


206  CIVIC  BIOLOGY 

The  table  on  the  precedmg  page  will  enable  the  beginner 
to  place  any  agaric  in  its  proper  genus,  and  indicates  the 
genera  that  contain  edible  species.  The  other  families,  espe- 
cially the  puffballs,  morels,  boleti,  coral  and  hedgehog  mush- 
rooms, also  contain  many  edible  species.  In  fact,  almost  all  of 
them  that  are  agreeable  to  the  taste  are  perfectly  safe  if  taken 
in  prime  condition.  All  the  soft-skinned  puffballs,  if  perfectly 
white  to  the  center,  are  free  from  suspicion,  as  are  all  the 
morels,  all  the  hydnums,  and  all  but  one  of  the  coral  mush- 
rooms —  Clavaria  dichofoma,  a  rare,  pure-white  form,  in  which 
all  the  branches  fork  regularly.  Among  the  boleti  the  group 
luridi,  characterized  by  red  mouths  of  the  tubes,  contain 
species  that  are  rated  as  poisonous. 

Raising  mushrooms  is  a  growing  industry.  Can  members  of 
the  class  visit  local  mushroom  cellars  and  report  on  methods 
employed  ?  If  none  are  grown  locally,  cannot  a  committee  of 
the  class  try  the  experiment  as  an  industrial  project  ?  Several 
of  the  state  experiment  stations  and  the  United  States  agri- 
cultural department  publish  bulletins  that  will  give  the  neces- 
sary information. 

As  a  people  we  are  permitting  a  considerable  food  supply  to 
go  to  waste.  As  we  study  the  matter,  can  we  estimate  the 
amount  and  value  of  the  mushrooms  that  grow  annually  on 
our  home  premises  and  in  our  gardens,  lawns,  woods,  and 
meadows?  What  might  these  figures  be  for  our  township, 
county,  and  state? 


CHAPTER  XX 

FUNGOUS  AND  BACTERIAL  DISEASES  OF  PLANTS 

Estimates  which  have  been  placed  upon  the  damage  caused  by  preva- 
lent plant  diseases  during  a  single  season  amount  frequently  to  a  very  con- 
siderable per  cent  of  the  total  value  of  the  crops.  In  the  United  States 
alone  the  destruction  wrought  by  fungous  diseases  is  sometimes  not  far  from 
half  a  billion  dollars.  — Duggar,  "Fungous  Diseases  of  Plants,^'  pp.  7-8 

Civic  aspects.  Line  fences  of  farm  or  city  lots  offer  no 
barriers  to  clouds  of  fungus  spores  in  the  air.    So  the  spores 

Fig.  99.    Mummied  plums  destroyed  by  brown  rot  (Sderotinia  fructigena). 
At  left,  tumor  on  branch,  caused  by  black  knot  {Plowrigfdia  morbosa) 

of  rusts  and  smuts  of  grains  may  sweep  over  the  fields  from 
Texas  to  Manitoba,  or  they  may  live  unseen  on  seeds  and 
thus  be  distributed  the  world  over.  The  spores  or  myce- 
lium, as  is  the  case  with  smut  of  corn  and  onion,  scab  and 
rot  of  potato,  and  clubroot  of  cabbage  and  turnip,  may  re- 
main alive  in  the  soil  from  year  to  year.  Such  fungi  can 
be  controlled  only  by  strict  rotation  of  crops.  We  thus  be- 
gin  to   realize  the   size   of   our  problem  in  its   world-wide 

207 


208  CIVIC  BIOLOGY 

scope,  and  may  be  prepared  to  conclude  that  its  final  solution 
must  depend  on  intelligent,  world-wide  cooperation. 

Irish  famine.  It  was  the  great  famine  in  Ireland  in  1845- 
1847  that  opened  the  eyes  of  the  whole  world  to  what  a 
fungous  disease  of  a  plant  might  mean  to  a  people,  and  the 
awakening  that  followed  marks  the  beginning  of  modern 
plant  pathology.  *  The  case  illustrates,  too,  the  apparent 
suddenness  of  the  attack,  and  also  the  total  destruction  of 
the  crop  the  second  year  if  rotation  is  not  resorted  to. 
Ireland  had  become  densely  populated,  a  large  part  of  the 
people  were  almost  wholly  dependent  on  the  potato  for 
food,  and  the  fungus  that  caused  the  famine  was  the  late 
blight,  or  rot,  of  the  potato  —  PhytopTithora  irifestans. 

The  harvest  of  1845  [»roiuised  to  be  the  richest  gathered  for  many 
years.  Suddenly,  in  one  short  month,  in  one  week  it  might  be  said, 
the  withering  breath  of  a  simoom  seemed  to  sweep  the  land,  blasting 
all  in  its  path.  I  myself  saw  whole  tracts  of  potato  growth  changed  in 
one  night  from  smiling  luxuriance  to  a  shriveled  and  blackened  waste. 
A  shout  of  alarm  arose.  But  the  buoyant  nature  of  the  Celtic  peasant 
did  not  yet  give  way.  The  crop  was  so  profuse  that  it  was  expected 
the  healthy  portion  w^ould  reach  an  average  result.  Winter  revealed 
the  alarming  fact  that  the  tubers  had  rotted  in  pit  and  storehouse. 
Nevertheless  the  farmers,  like  hapless  men  who  double  their  stakes 
to  recover  losses,  made  only  more  strenuous  exertions  to  till  a  larger 
breadth  in  1846.  Although  already  feeling  the  pinch  of  sore  distress, 
if  not  actual  famine,  they  w^orked  as  if  for  dear  life ;  they  begged  and 
borrowed  on  any  terms  the  means  whereby  to  crop  the  land  once  more. 
The  pawn  offices  were  choked  with  the  humble  finery  that  had  shone 
at  the  village  dance  or  the  christening  feast ;  the  banks  and  money- 
lenders were  besieged  with  apjwals  for  credit.  Meals  were  stinted, 
backs  were  bared.  Anything,  anything  to  tide  over  the  interval  to 
the  harvest  of  "Forty-six."  O  God,  it  is  a  dreadful  thought  that 
all  this  effort  was  but  more '  surely  leading  them  to  ruin !  It  was 
this  harvest  of  Forty-six  that  sealed  their  doom.  Not  partially  but 
completely,  utterly,  hopelessly,  it  perished.  As  in  the  previous  year, 
all  promised  brightly  up  to  the  close  of  July.  Then,  suddenly,  in  a 
night,  whole  areas  were  blighted;    and   this  time,  alas!    no   portion 


I 


FUNGOUS  AND  BACTEKIAL  DISEASES  209 

of  the  crop  escaped.  A  cry  of  agony  and  despair  went  up  all  over 
the  land.  The  last  desperate  stake  for  life  had  been  played  and  all 
was  lost.  The  doomed  people  realized  but  too  well  what  was  before 
them.  Last  year's  premonitory  sufferings  had  exhausted  them  and 
now?  —  they  must  die. 

We  raised  a  public  subscription,  and  employed  two  men  with  horse 
and  cart  to  go  around  each  day  and  gather  up  the  dead.  One  by  one 
they  were  taken  to  a  great  pit  at  Ardnabrahair  Abbey  and  dropped 
through  the  hinged  bottom  of  a  trap-coffin  into  a  common  grave 
below.  In  the  remoter  rural  districts  even  this  rude  sepulcher  was 
impossible.  In  the  field  and  by  the  ditchside  the  victims  lay  as  they 
fell,  till  some  charitable  hand  was  found  to  cover  them  with  the 
adjacent  soil.  —  Lord  E.  Fitzmaurice  and  J.  R.  Thursfif.ld,  in 
Lamed's  "History  for  Ready  Reference,"  Ireland,  1845-1847 

Here  we  have  our  problem  in  the  large  and  m  concrete 
form.  An  enemy  has  killed  by  starvation  nearly  a  million 
people.^  What  is  this  enemy  ?  Who  saw  it  come  or  go  ? 
How  does  it  operate  ?  Why  did  it  do  this  ?  How  can  we 
prevent  future  calamities  of  this  kind  ?  The  world  had  to 
await  alleviation  of  fears  and  superstitions,  discoveries  in 
many  fields,  and  growtli  of  the  science  of  botany  before 
many  of  these  questions  could  be  answered.  Nothing  can 
surpass  in  human  value  and  interest,  however,  the  quality 
of  mind  that  works  out  solutions  for  such  problems.  In  the 
light  of  the  Irish  famine,  what  may  be  the  human  value  of 
such  discoveries  ? 

I'o  get  an  insight  into  growth  of  knowledge  in  this  field,  call  for  at 
least  three  volunteers.  Let  number  one  read  up  the  story  of  this 
famine  further  and  report  to  the  class.  This  is  to  develop  a  feeling 
for  the  need  and  motive  for  such  study.  Let  number  two  look  up  and 
report  -on  the  story  of  discoveries  leading  up  to  determining' and 
naming  the  fungus  and  devising  methods  for  its  control.^    Number 

1  Returns  to  date  (September  15,  1915)  give  total  losses,  killed,  wounded, 
and  missing  in  the  British  army,  after  more  than  a  year  of  the  great  war, 
at  less  than  400,000. 

2  See  work  of  Dr.  Berkeley  (1846),  Louis  Pasteur  (1856),  especially  De 
Bary  (1861  and  later),  and  Millardet,  discoverer  of  Bordeaux  mixture  (1883). 


210  CIVIC  BIOLOGY 

three  may  collect  specimens  showing  all  stages  of  infestation  of  leaves 
and  tubers  for  actual  demonstration,  make  pictures  of  the  fungus  and 
diagrams  showing  how  it  attacks  the  potato  plant,  and  finally  give  the 
best  methods  for  its  control. 

Infection.  The  process  of  infection  is  as  simple  as  that  of 
planting  seeds  in  a  garden  plot  and  raising  the  particular 
kind  of  flower  or  vegetable  or  of  inoculating  mold  spores  in 
any  sort  of  food  cultures.  The  spores  of  the  parasite  germi- 
nate in  contact  with  their  host  plant,  and  the  hyphse  enter 
through  wounds  or  stomata  or  actually  eat  their  way  through 
the  cells  of  the  surface. 

In  order  to  develop  perfectly  clear  ideas,  perform  all  sorts  of  in- 
oculation experiments  with   fungi  that  happen  to  be   available.    Let 
members  of  the  class  use  different  kinds   and  demonstrate  methods 
and  results.    Use  any  of  the  following,  or  others  of  local  importance. 
Inoculate  by  touching  point  of  pin  to  spores  and  pricking  surface  : 
A  potato  tuber  or  leaf  with  spores  of  blight  or  scab ; 
Seedlings  of  corn,  or  other  grains,  with  smuts  or  rusts ; 
Lettuce  plants  with  spores  of  "drop"  (Sclerotinia   Ubertiand)   if 

locally  important ; 
An  apple  with  spores  of  bitter  rot ; 
A  plum,  peach,  or  cherry  with  spores  of  brown  rot  (Sderotima 

fructigend),  always  at  hand  everywhere ; 
Bean    seedlings    with    germs    of    bacterial    blight    (Pseudomonaa 
phaseoli)  or  spores  of  pod  spot  or  anthracnose  (ColletotricJium 
lindemuthianum^. 
In   these    days    of    quack  nostrums,    illogical    thinking,    and   even 
hysterical   denial   of   cause   and   effect   in   matters   of   disease,  these 
lessons  wdth  plants,  which  are    not  subject   to    fears    and   perverted 
mentality,  may  help  to  keep  us  sane. 

Wound  infection  of  trees.  A  search  through  the  orchard 
or  wood  lot  is  all  too  likely  to  show  trees  with  mushrooms 
of  different  kinds  —  polypori,  hydnums,  oyster  and  honey 
mushrooms  —  growing  upon  trunks  or  roots.  Inspection 
seldom  fails  to  reveal  the  wound  in  the  bark  through  which 
the  fungus  entered  the  wood.     It   is   probable    that   these 


rUKGOUS  AND  BACTEKIAL  DISEASES 


211 


parasites  destroy  more  timber  annually  than  do  forest  fires. 
The  visible  portions,  the  sporophores,  of  these  tree-destroying 
fungi  are  pushed  out  at  certain  seasons,  or  during  certain 
weather  conditions,  and  pour  clouds  of  spores  into  the  air  to 
infect  surrounding  trees.  These  disease  breeders  should  be 
the  first  to  be  made  into  firewood  in  annual  cutting  from  the 
wood  lot.  The  sporophores  should  also  be  destroyed  as  soon 
as  they  appear.  By  a  little  intelligent  cooperation  a  commu- 
nity could  bring  these  pests  under  control,  and  however 
valuable  the  trees  may 
be  in  themselves,  the 
study  will  be  worth 
while  as  an  example 
of  spread  and  preven- 
tion of  disease. 

Koot  rot  of  fruit  trees 
is  a  matter  that  will  call 
for  special  attention  in 
certain  sections.  Two  con- 
spicuous mushrooms,  Cli- 
tocyhe  parasitica  and  the 
common  honey  mush- 
room (Armillaria  mellea),  show  strong  parasitic  tendencies  when  .brought 
into  contact  with  the  roots  or  crowns  of  apple,  peach,  or  cherry  trees. 
In  clearing  land  for  orchards  it  is  advisable  to  remove  all  stumps  and 
roots  that  are  likely  to  harbor  these  fungi. 

Invite  the  local  forester  or  tree  surgeon  to  discuss  these  problems 
with  the  class.  Learn  from  him  the  best  treatment  for  tree  wounds. 
(Wounds  of  any  size  made  in  pruning  should  be  sealed  with  paint  or 
gas  tar.)  As  laboratory  work  let  the  class,  in  convenient  groups,  make 
some  experiments  in  tree  surgery  where  most  needed  about  homes, 
school  yard,  or  streets. 

Civic  types  for  study.  Duggar  describes,  or  mentions,  in 
his  book  "  Fungous  Diseases  of  Plants,"  238  fungi  that 
attack  the  common  plants  and  trees  of  forest,  orchard, 
garden,  and  field.     He  also  gives  a  most  useful  Host  Index 


Fig.  100.    Apple    inoculated,   at   pin,   with 

spores  of  brown  rot  from  mummied  plum. 

Control  apple 

As  instructive  as  a  case  of  smallpox 


212 


CIVIC  BIOLOGY 


(the  host  is  the  organism  that  supports  a  parasite),  iii 
which  he  lists  174  plants,  with  the  fungi  that  attack  each. 
From  this  we  see  that  everything  we  try  to  raise  has  its 
fungus  enemies :  alfalfa  has  anthracnose,  leaf  spot,  root  gall, 
European  root  disease,  and  root  rot ;  the  apple  has  24,  among 
them  anthracnose,  or  bitter  rot,  fire  blight,  crown  gall,  rust, 

and  scab ;  beans  have  7  ; 
corn,  6 ;  cotton,  9 ;  the 
grape,  9  ;  potato,  6  ; 
tomato,  8  ;  wheat,  7 ; 
violet,  6 ;  pine,  6 ;  oak, 
7;  and  so  on  through 
the  list. 

The  following  bacte- 
rial diseases  are  common : 
Pear  and  apple  blight. 
Leaves  turn  brown  as 
though  burned  with  fire. 
The  germ  was  supposed 
to  be  carried  by  bees  to 
the  blossoms,  but  it  is 
probably  inoculated  by 
aphides.  Limbs  that  show  symptoms  of  the  disease  should 
be  cut  below  traces  of  the  blight  and  burned. 

Wilt  disease.  This  disease  affects  tomatoes,  cucumbers, 
melons,  cotton,  and  Irish  potatoes,  and  causes  the  plants  to 
wilt  rapidly  and  die. 

Black  rot  of  cabbage.  The  germ  attacks  cabbage,  turnips, 
rutabaga,  and  cauliflower.  Leaves  turn  black  and  the  plant 
dies.     This  disease  is  common  in  America  and  Europe. 

Try,  at  least,  to  make  a  preliminary  survey,  and  then 
choose  for  intensive  study  the  local  types  that  are  most  im- 
portant, and  especially  those  that  require  general  knowledge 
and  united  effort  of  the   com  muni  tv  to  control  —  the  civic 


Fig.  101.   Loose  smut  of  oats  {Ustilago 
avencB)  and  normal  heads 


FUNGOUS  AND  BACTERIAL  DISEASES 


213 


types.  It  may  be  possible  for  each  pupil  to  make  a  table 
giving  for  each  fruit,  vegetable,  and  farm  crop  the  loss  caused 
by  fungi  —  that  is,  to  answer  the  question,  What  part  of  the 
half -billion-dollar  tax  does  my  home  pay?  A  suggestion  for 
such  a  table  is  given  below. 


Losses  Caused  by  Fungi  on  a  Gkain  Farm  of  320  Acres  ^ 


!  Number 
j  OF  Acres 

Yield  in 
Bushels 

Per  Cent 
Injured 

Price 

Price  of 
Smutted 

Total  Loss 

Wheat .     . 
Oats     .     . 
Corn     .     . 
Potatoes    . 
Orchard    . 

280 
40 

.  1         10 

•  !          ^ 
4 

47 
30 

75 
48 

17 
10 

7 
75 

11.30 
.40 
.75 
.50 

#.85 

$8,843.80 
140.80 

42.00 
144.00 

26.50  2 

Total    . 

•    ! 

$9,197.10 

National  and  world  problem.  The  general  situation  is  aptly 
expressed  by  the  complamt  heard  on  every  hand: 

The  world  is  not  fit  to  live  in  any  more,  and  it 's  getting  worse  and 
worse  every  year.  We  never  used  to  hear  about  all  these  new-fangled 
diseases  all  the  time,  and  everything  didn't  use  to  rot  and  smut  and 
blight  when  I  was  a  girl  back  on  the  old  farm. 

This  is  literally  true  and  for  several  good  reasons.  People 
(lid  not  then  know  what  was  eating  them  out  of  house  and 


1  Wheat  is  supposed  to  be  affected  with  stinking  smut,  which  Duggar  says 
sometimes  takes  "from  one  half  to  two  thirds  of  a  crop"  of  some  sections. 
Loose  smut,  corn  smut,  and  early  blight  are  the  fungi  supposed  to  have 
attacked  the  oats,  corn,  and  potatoes  respectively.  Estimates  are  not  ex- 
cessive. The  percentages  for  the  wheat,  oats,  and  corn  are  figured  by  count- 
ing 100  stalks  taken  at  random  in  ten  different  parts  of  the  field.  (Save 
several  of  these  bundles  of  wheat  or  oats  for  demonstration  in  the  labo- 
ratory and  at  neighborhood  meetings.)  The  potatoes  are  estimated  from 
usual  results  in  case  of  sprayed  and  unsprayed  field  plots.  The  cost  of 
treating  the  wheat  and  oats  with  formalin  would  have  been  a  trifling 
insurance  against  the  loss  incurred. 

^  Cost  of  three  sprayings  and  one  pruning  for  blight,  bitter  rot,  etc. 


214 


CIVIC  BIOLOGY 


home.    They  called   it  Providence  and  did  not  talk  about 
it.     Again,  modern  commerce  and  travel  are  rapidly  mixing 


Fig.  102.   Tree  (on  the  right)  infected  with  peach  yellows 

Peach  yellows  is  a  contagious  disease,  exterminative  of  the  peach  in  northeastern 

United  States,  that  has  baffled  all  attempts  to  discover  its  cause.   The  tree  shown 

on  the  right  is  in  the  last  stages  of  the  disease ;  the  one  on  the  left  is  healthy 

the  bacteria,  fungi,  and  insects  of  all  the  world,  and  these  are 
the  forces  that  have  often  determined  both  the  floras  and  the 
faunas  of  continents.     More  American   Indians  have  been 


FUNGOUS  AND  BACTERIAL  DISEASES  215 

killed  by  European  bacteria  than  by  bullets.  Measles  struck 
the  Fiji  Islands  like  a  deadly  pestilence.  So  we  inspect  and 
quarantine  against  the  importation  of  such  germs  as  those  of 
bubonic  plague,  Asiatic  cholera,  and  foot-and-mouth  disease, 
but  they  slip  by  in  spite  of  all  precautions.  The  canker,  or 
chestnut-bark  disease,  appeared  about  ten  years  ago,  coming 
probably  from  Japan.  Working  as  it  does,  between  wood 
and  bark,  it  cannot  be  reached  by  sprays,  and  there  are 
not  men  enough  available  to  prune  and  burn  the  diseased 
trees.  It  is  said  to  have  destroyed  over  $30,000,000  worth 
of  chestnut  trees,  and  predictions  appear  to  be  well  founded 
that  it  may  not  leave  a  single  one  alive  in  eastern  North 
America.  1  A  third  reason  is  that  we  are  planting  large  areas 
to  the  same  crop,  with  field  against  field.  This  is  like  piling 
up  kindling  for  a  fire,  when  a  disease  gets  a  start. 

Control  measures.  Methods  are  improving  continually,  and 
the  only  safe  course  to  pursue  in  this  field  is  to  correspond 
with  our  nearest  experiment  station  and  secure  their  latest 
spray  calendars,  take  the  monthly  list  of  publications,  and 
keep  abreast  of  discoveries.  The  underlying  principles,  how- 
ever, should  be  generally  understood. 

1.  Be  sure  to  plant  healthy,  uninfected,  free-from-disease  seeds, 
tubers,  bulbs,  or  nursery  stock.  This  refers  to  germs  of  disease  inside 
the  seed,  tuber,  or  stock,  and  applies,  of  course,  to  buds  and  scions. 

Peach  yellows,  while  the  germ  has  not  been  discovered,  is  known  to 
be  transmitted  from  diseased  trees  in  seeds,  buds,  or  scions.  Wilt  dis- 
ease of  sweet  corn,  or  Stewart's  disease,  sometimes  destructive  to  from 
80  per  cent  to  100  per  cent  of  the  crop,  is  transmitted  on,  and  prob- 
ably in,  the  seed.  Seed  should  not  be  saved,  or  distributed  to  uncon- 
taminated  land,  from  infected  fields.  The  same  is  true  of  anthracnose 
of  beans  and  cotton ;  bean  blight ;  bacterial  blight,  or  wilt,  of  potato ; 

1  The  species  might  be  saved  to  the  continent  if  nuts  from  sections  as 
yet  uninfected  could  be  sent  to  suitable  places  on  the  Pacific  coast  and 
planted  and  reared  beyond  probable  reach  of  infection.  The  United  States 
Bureau  of  Forestry  would  probably  be  glad  to  supply  safe  seeds  to  biology 
classes  that  would  agree  to  follow  out  directions  for  planting  and  culture. 


216 


CIVIC  BIOLOGY 


late  blight,  or  rot,  and  dry  rot,  or  stem  blight,  of  potato  ;  and  crown  gall 
of  grapes,  berry  bushes,  and  fruit  trees.  80,  too,  pear  and  apple  blight 
have  often  been  scattered  broadcast  from  nurseries  because  disinfec- 
tion of  pruning  tools  was  neglected.  In  general,  disiease  shows  u}) 
clearly  in  the  nursery  or  field,  W'hile  it  would  require  bacteriological 
and  microscopic  methods  to  find  the  germs  within  the  seeds  or  stocks. 
Go  out  and  hunt  over  local  nurseries  or  seed  farms.  Ask  experts  from 
them  to  come  in  and  demonstrate  and  discuss  their  methods.   All  W'ho 


Fig.  103.    Corn  smut  {Ustilago  zece) 

l)ropose  to  distribute  these  important  supplies  to  the  public  ought  to 
know  their  business  by  this  time.  The  best  firms  employ  trained  ex- 
perts to  see  to  it  that  stock  is  free  from  disease,  and  then  they  may 
send  it  to  branch  farms,  far  away  from  any  possible  contamination,  to 
have  it  propagated  for  the  market. 

2.  If  spores  are  alive  on  the  seeds  or  tubers,  ready  to  attack  the 
embryo  plant  when  it  germinates,  kill  them  before  planting. 

Scab  of  potatoes  and  smuts  of  grains  are  examples.  Soak  seed  potatoes 
for  two  hours  in  formalin  solution  (1  ounce  to  2  gallons  of  water)  or  in 
mercuric  chloride  (corrosive  sublimate)  solution  (1  ounce  to  8  gallons  of 
w^ater).  External  spores  of  the  smuts  on  wheat,  oats,  and  barley  are 
killed  by  soaking  for  from  ten  to  twenty  minutes  in  formalin  solution 
(1  pint  to  30  gallons  of  water)  or  by  warming  up  the  seed  in  water  at 
110°-120°  and  then  holding  it  for  ten  minutes  in  water  at  132°-133°  F. 


FUNGOUS  AND  BACTEKIAL  DISEASES  217 

'i.  If  living  spores  arc  coiitiimally  sifting  down  from  the  air,  we 
must  keep  the  surface  of  leaf  or  fruit  covered  with  something  that 
will  kill  them  as  they  germinate.  If  we  wait  till  they  get  in,  the  crop 
will  be  ruined.  Various  Bordeaux  solutions  and  lime-sulfur  washes  are 
effective  for  this  purpose,  and,  naturally,  while  leaves  are  unfolding 
rapidly  or  fruit  is  growing,  we  must  spray  every  few  days. 

4.  If  the  spores  are  alive  in  the  soil,  there  is  nothing  to  do 
but  rotate.  Plant  something  they  cannot  grow  upon  —  something  that 
will  starve  tliem  out ;  there  is  no  other  way  of  killing  them  out  of 
the  ground. 

5.  Seek  continually  for  resistant  varieties  and  strains.  With  every- 
body on  the  lookout  for  these  valuable  variations,  we  may  hope  for 
more  rapid  progress  in  the  control  of  fungous  diseases  of  plants. 

6.  Observe  general  soil  and  plant  hygiene.  With  the  soil  mellow  and 
well  drained  we  may  minimize  danger  from  root  rots  and  damping-off 
fungi ;  with  plants  well  spaced  to  let  in  sunlight  and  allow  free  circu- 
lation of  air,  or  pruned  with  this  in  view,  and  witli  fruits  thinned  so  as 
not  to  touch,  we  may  greatly  reduce  danger  from  air-ltorne  spores. 

Every  cominuiiity  organization,  rnral  or  suburban,  ougbt 
to  have  a  committee  on  fungous  diseases  of  plants  aiid  their 
practical  control.  The  local  class  in  biology  might  well  be 
the  laboratory  right  arm  of  such  a  committee.  By  working 
out  cooperative  plans,  thoroughly  agreed  upon,  which  might 
spread  from  neighborhood  to  neighborhood  as  they  were  de- 
veloped and  perfected,  many  of  our.  Avorst  fungus  enemies 
might  be  completely  stamped  out.  No  real  estimate  of  the  loss 
caused  by  them  has  ever  been  even  attempted.  We  do  not 
know  enough  about  them.  Duggar's  guess  of  1500,000,000 
a  year  is  very  low,  and,  while  it  might  approximate  the  losses 
to  tlie  large  markets  and  channels  of  trade,  we  must  certainly 
add  to  this  all  the  damage  to  the  home  garden  and  orchard, 
with  the  labor  and  expense  of  fighting  fungi  in  them.  The 
class  in  civic  biology  which  gives  us  even  a  first  attempt  at 
a  detailed  account  of  the  expenses  and  losses  chargeable  to 
fungous  diseases  of  plants  in  any  community  will  mark  a 
distinct  forward  move  in  tliis  field. 


CHAPTER  XXI 
BACTERIA 

Size.  Bacteria,  the  smallest  plants  known,  range  in  size 
from  ultramicroscopic  to  6  microns  thick  by  80  microns  long. 
Even  the  largest  single  bacterium  known  is  far  too  small  to 
be  seen  with  the  unaided  eye,  and  for  the  smaller  species, 
like  the  germ  of  grippe.  Bacillus  influenzce,  which  is  .3  />«,  thick 
by  .75  fjb  long,  we  might  have  2,867,417,289  spread  in  a 
single  layer  over  one  square  inch  of  finger  tip,  and  the 
smear  might  be  even  100  germs  deep,  that  is,  contain 
286,741,728,900  bacteria,  and  still  be  invisible  to  the  eye 
and  too  thin  to  feel. 

Form.  Bacteria  appear  under  the  microscope  as  spherical 
(the  micrococci),  as  slender  rods  (the  bacilli),  and  as  forms 
bent  like  commas  or  twisted  into  spirals  (the  spirilla). 
Humorously  they  are  said  to  resemble  "  balls,  cues,  and 
corkscrews." 

Distribution.  Bacteria  are  everywhere  in  nature  except  in 
the  air  at  high  altitudes,  over  perpetual  snows  and  over  mid- 
ocean,  in  the  deeper  layers  of  sand  or  clay  soils  (they  may 
be  carried  to  almost  any  depth  and  almost  any  distance  by 
streams  in  crevices  of  rocks),  and,  most  important  of  all, 
in  the  blood  or  sap  and  internal  tissues  of  healthy  animals 
and  plants. 

Bacteria  of  the  air.  Bacteria  are  blown  about  as  free  dust 
with  every  current  of  air.  The  table  on  the  next  page,  made 
in  France  from  data  collected  monthly  for  ten  years,  shows 
the  variation  in  number  of  bacteria  in  the  air  of  city  and 
country  at  different  seasons  of  the  year. 

218 


BACTERIA  219 


j  Country  Bacteuia 

City  Bacteria 

Winter 

Spring 

170 
295 
345 
195 
250 

4,305 
8,080 
9,845 
5  6H5 

Autumn 

Average 

6,975 

Bacteria  of  water.  Streams  ordinarily  contain  about  500 
bacteria  per  cubic  centimeter,  collected  from  the  air  and  soil 
over  the  area  drained.  The  river  Seine,  as  it  enters  Paris,  has 
about  300  bacteria  per  cubic  centimeter,  but  after  it  receives 
the  sewage  from  this  city  it  contains  200,000  bacteria  per  cu- 
bic centimeter.  The  supposed  self-purification  of  streams  is 
found  to  be  mainly  due  to  dilution.  Experts  are  impounding 
running  water  in  reservoirs  previous  to  supplying  cities,  since 
bacteria  disappear  from  still  water.  JNIicroscopic  organisms 
(plankton)  upon  which  young  fishes  feed  are  found  in  greater 
abundance  in  quiet  water,  and  it  is  thought  that  they  in  turn 
feed  upon  bacteria. 

Water  in  wells  varies  greatly  in  number  of  bacteria.  Arte- 
sian wells  are  practically  free  from  them  ;  ordinary  wells  may 
contain  from  1000  to  8000  bacteria  per  cubic  centimeter.  Ice 
varies  in  number  of  bacteria  according  to  water  from  which  it  is 
taken.  Clear  ice  from  the  Hudson  River  contained  398  bacteria 
per  cubic  centimeter,  while  its  snow  ice  contained  9187.  Why  ? 

Bacteria  of  the  soil.  The  number  of  bacteria  of  the  soil 
varies  with  the  amount  of  moisture  and  organic  debris.  Su- 
perficial layers  contain  from  10,000  to  5,000,000  bacteria  per 
gram;  if  polluted  with  organic  debris,  they  may  contain  as 
high  as  100,000,000  per  gram.  The  number  of  bacteria  di- 
minishes rapidly  as  we  pass  down  into  the  earth ;  at  a  depth 
of  from  ten  to  fifteen  feet  few  if  any  can  be  found.  This  is 
the  reason  that  in  many  cities  water  is  passed  through  sand 
filters  before  it  is  used  for  drinking  purposes. 


220  CIVIC  BIOLOGY 

Reproduction  in  bacteria.  Bacteria  multiply  by  division, 
which  is  even  more  simple  than  the  budding  of  yeast.  The 
cell,  when  mature,  divides  transversely  into  equal  halves. 
Under  favorable  conditions  a  bacterium  may  divide  every 
twenty  minutes  to  half  an  hour.  Can  you  calculate  the 
progeny  of  a  single  bacillus  for  twenty-four  hours  ? 

Bacteria  do  not  grow  and  reproduce  without  food,  and  their 
astonishing  power  of  multiplication  helps  us  to  understand  the 
altered  condition  of  milk  and  meat  if  kept  in  a  warm  place  for 
even  a  few  hours. 

Some  species  develop  spores  within  the  cell  and  these  are 
much  more  difficult  to  kill  than  the  bacteria  themselves. 

Conditions  favorable  for  the  multiplication  of  bacteria.  Like 
other  plants,  bacteria  demand  food,  moisture,  oxygen,  and 
warmth  for  growth.  Remove  any  one  of  these  conditions  and 
they  will  either  cease  to  multiply  or  die. 

Moisture.  Bacteria  grow  only  in  liquids  or  moist  sub- 
stances. Dry  foods  and  those  containing  less  than  20  or  30 
per  cent  of  water  they  cannot  attack.  Drying  weakens  and 
kills  many  bacteria.  Spores,  however,  are  much  more  resis- 
tant to  continued  drying  than  the  vegetative  or  growing  cell. 

Why  should  houses  not  be  allowed  to  become  damp?  Why  is  meat 
salted  and  dried?  Why  is  canned  fruit  sealed?  AVhat  influence  has 
sugar  in  preserving  frtiit?  Why  are  such  foods  as  molasses,  condensed 
milk,  flour,  seeds,  and  grain  bacteria-proof? 

Temperature.  Temperature  affects  growth  of  bacteria.  As 
in  higher  plants,  there  is  a  temperature  known  as  the  optimum 
at  which  each  species  thrives  best.  A  tubercle  bacillus  grows 
within  a  range  of  5  degrees,  while  a  few  other  species  can 
grow  anywhere  within  a  range  of  50  degrees. 

Bacteria  do  not  multiply  during  the  time  they  are  exposed 
to  low  temperature,  but  their  vitality  is  not  affected ;  the  tu- 
bercle bacillus  has  been  exj^osed  to  a  temperature  of  liquid  air 


BACTERIA  221 

(—190°  C.)  for  periods  varying  from  six  hours  to  forty-two 
days  without  kilhng  it.  The  retardation  of  bacterial  growth 
in  low  temperature  is  of  importance  from  the  public-healtli 
standpoint,  since  it  makes  possible  the  shipping  and  temporary 
preserving  of  perishable  foods  in  cold  storage. 

Heat  in  sufficient  amount  kills  all  bacteria  whether  in  the 
spore  or  vegetative  state.  Steam  heat  is  more  effective  than 
dry;  a  few  minutes  of  steam  heat  at  120°  C.  will  kill  spores 
that  would  take  180°  C.  of  dry  heat  to  destroy. 

Light.  Contrary  to  the  effect  produced  upon  green  plants, 
light  has  an  unfavorable  action  upon  bacteria.  Bright  sunlight 
serves  to  kill  the  vegetative  cell  and  weakens  the  spores ; 
diffuse  light  retards  growth ;  in  the  absence  of  all  light  they 
grow  best.  This  destructive  action  is  intensified  by  moisture 
and  fresh  air. 

Oxygen.  Pasteur  was  the  first  to  demonstrate  that  some 
bacteria  live  without  free  oxygen.  He  divided  all  bacteria  into 
three  classes :  aerobic,  those  species  that  can  grow  only  in  the 
presence  of  air;  anaerobic,  those  that  can  grow  only  in  the 
absence  of  air ;  and  facultative,  those  that  can  grow  either 
with  or  Avithout  air.  Bacteria  that,  grow  in  the  inner  tissues 
of  the  body  of  a  plant  or  animal  are  examples  of  anaerobic 
species ;  they  do  not  grow  without  oxygen,  but  get  a  supply 
by  breaking  down  organic  substances  that  contain  it.  The 
majority  of  bacteria  are  aerobic,  as  evidenced  by  the  many 
cases  of  decay  which  begin  on  the  surface  and  work  toward 
the  center. 

Work  of  bacteria.  Like  other  fungi,  bacteria  are  parasitic 
(attacking  living  plants  and  animals),  saprophytic  (feedhig 
upon  dead  or  waste  animal  or  plant  matters),  and  symbiotic 
(living  in  plants  to  the  mutual  benefit  of  bacterium  and 
plant).  Because  some  species  can  attack  living  tissue  and 
produce  disease,  all  bacteria  have  come  to  suggest  disease 
to  the   popular  mind.     This  reputation  is  as  unjust  to  the 


222 


CIVIC  BIOLOGY 


saprophytic  bacteria  as  it  would  be  to  condemn  all  higher 
plants  because  a  few  of  them  are  poisonous.  In  general,  sap- 
rophytic bacteria  do  no  more  harm  than  dust  if  breathed,  or 
than  vegetables  if  eaten. 

Nitrifying  bacteria.  Certain  bacteria  of  the  soil  are  symbi- 
otic upon  the  roots  of  leguminous  plants,  such  as  clover,  alfalfa, 

beans,  and  peas,  and  cause 
tubercles  to  form.  These 
bacteria  gain  entrance 
through  the  root  hairs 
of  the  plant  and  cause 
smooth  young  roots  to  as- 
sume a  nodular  appear- 
ance (Fig.  104). 

Experiment  shows  that 
if  a  legume,  notably  clo- 
ver, is  grown  upon  soil  of 
known  composition,  a  part 
of  which  has  been  ster- 
ilized (baked),  the  crop 
upon  the  un sterilized  soil 
will  be  notably  larger  and 
the  soil  will  have  nitro- 
gen added  to  it.  .These 
bacteria  are  important, 
since  they  can  fix  the  free  nitrogen  of  the  air  and  give  it  to 
tlie  soil  in  the  form  of  nitrates.  The  benefit  to  the  soil  result- 
ing from  clover  cropping  was  discovered  and  practiced  by 
farmers  long  before  the  cause  was  known. 

Much  experimental  work  is  being  done  with  these  nitrifying 
bacteria,  and  pure  cultures  are  being  sold  to  inoculate  soil 
that  does  not  contain  them.  To  prevent  extravagant  and  mis- 
leading claims  of  dealers,  the  United  States  government  has 
issued  the  following  statements  ;  "  No  beneficial  results  can  be 


Fig.  104.    Clover  plant  with  many 
bacterial  nodules  on  roots 


BACTERIA  223 

expected  for  a  particular  crop  if  the  bacteria  for  the  crop  are 
already  in  the  soil.  But  little,  if  any,  benefit  can  be  expected 
from  the  use  of  these  bacteria  if  the  ground  is  decidedly  in 
need  of  other  fertilizers,  such  as  phosphates,  potash,  and  lime. 
But  little,  if  any,  benefit  can  be  expected  from  inoculation  if 
the  soil  is  already  rich  in  nitrogen." 

Carefully  wash  the  roots  of  different  clover  plants.  Are  the  nodules 
of  nitrifying  bacteria  present?  Are  they  found  upon  alfalfa  and  peas  in 
your  region?  Are  pure  cultures  of  these  bacteria  sold  in  your  state? 
Read  the  state  and  government  bulletins  upon  these  bacteria. 


CHAPTER  XXII 
BACTERIA  CONTINUED:    LABORATORY  METHODS 

Apparatus  and  material.  To  grow  bacteria  in  the  labora- 
tory the  following  apparatus  and  material  are  necessary :  a 
steam  sterilizer,  hot-air  sterilizer,  two  platinum  needles^;  test 
tubes,  Petri  dishes,  absorbent  cotton,  litmus  paper,  sheet  gela- 
tin, agar-agar,  extract  of  beef,  potatoes,  caustic  soda  solution, 
and  hydrochloric  acid. 

Gelatin  medium.  Dissolve  in  1000  cubic  centimeters  of 
distilled  water  10  grams  of  peptone,  5  grams  of  common  salt, 
2^  grams  of  beef  extract,  and  100  grams  of  sheet  gelatin,  and 
place  in  the  steam  sterilizer  until  dissolved. ^ 

Let  the  mixture  cool  to  55°  C.  (you  can  hold  it  in  your 
hand)  and  add  a  teaspoonful  of  albumen  dissolved  in  cold 
water,  or  the  whites  of  two  eggs.  Boil  until  the  liquid  looks 
clear.^  Line  a  funnel  witli  wet  absorbent  cotton  or  with  filter 
paper  designed  for  gelatin  or  agar-agar  filtration.  Pour  the 
gelatin  mixture  into  the  funnel  and  catch  in  a  sterilized 
flask.  Place  in  a  steam  sterilizer.  If  the  funnel  is  kept 
thoroughly  warm,  the  gelatin  will  pass  through  the  filter  in 
about  an  hour.  Test  the  gelatin  with  litmus  paper.  It  will 
be  found  to  be  acid.  Add  a  weak  solution  of  caustic  soda  to 
it,  drop  by  drop,  until  blue  litmus  paper  does  not  change 

1  Cut  platinum  wire  (No.  27)  into  two-inch  lengths.  Fuse  one  end  of  each 
into  a  glass  rod,  and  bend  the  free  end  of  one  of  the  needles  thus  made  into 
a  small  loop,  to  be  used  in  measuring  drops  in  liquid  cultures. 

2  A  portable  sheet-iron  oven  and  an  ordinary  steam  cooker  may  be  used 
if  necessary. 

8  A  fact  that  must  be  borne  in  mind  in  preparing  gelatin  is  that  its  gelat- 
inizing power  is  injured  by  prolonged  heating  during  the  process  of  prepa- 
ration or  sterilization,  and  is  lost  immediately  when  heated  to  140°  C, 

224 


BACTERIA  225 

color.  Pour  about  one  and  one-half  inches  of  gelatin  into  each 
test  tube  and  plug  with  cotton.  Sterilize  the  tubes  twenty 
minutes  for  three  consecutive  days,  so  as  to  kill  all  spores. 

Agar-agar  medium.  ^lix  the  same  as  the  gelatin  medium, 
using  15  grams  of  agar-agar  in  place  of  the  100  grams  of 
gelatin,  llie  preparation  of  agar-agar  medium,  however,  is 
more  troublesome  than  the  gelatin.  Agar-agar  does  not  dis- 
solve easily  and  is  difficult  to  filter.  To  obtain  a  quick  result  it 
is  best  to  perform  the  filtration  in  parts.  If  the  funnel,  lined 
with  absorbent  cotton,  is  well  heated,  about  one  half  of  the 
agar-agar  mixture  will  have  passed  through  the  filter  in  fifteen 
minutes.  Remove  the  funnel  and  reboil  the  remaining  agar- 
agar  and  pass  through  a  fresh  filter.  Repeat  the  process  until 
the  mixture  is  filtered.^ 

Potato  medium.  Pare  the  potatoes  and  cut  with  a  cork  borer 
of  suitable  size  for  the  test  tube.  Divide  the  cylinders  into 
two-inch  lengths  and  then  cut  diagonally  across.  Place  the 
''  potato  slants  "  thus  prepared  in  water  for  several  hours,  to 
extract  the  product  which  turns  them  black  when  exposed 
to  air. 

Put  into  test  tubes,  slant  side  uppermost,  plug,  and  sterilize 
in  a  steam  sterilizer  for  twenty-five  minutes  at  100  C.  for  three 
successive  days.  A  small  piece  of  glass  rod  placed  in  the  bottom 
of  the  test  tube  holds  the  potato  above  the  condensed  steam. 

Rules  and  methods  of  manipulation.  (1)  Learn  as  early  in 
the  course  as  possible  that  all  dishes  should  be  washed  and 
sterilized  in  the  hot-air  sterilizer  before  using.  All  micro- 
organisms are  killed  when  they  are  heated  as  follows :  three 
hours  at  150°  C,  or  until  paper  is  brown ;  one  half  hour  at 
160°  C;  one  fourth  hour  at  170°  C;  one  minute  at  190°  C. 
(2)    Before  sterilizing,  wrap  the  Petri  dishes  in  papei*  and 

1  If  time  is  limited,  obtain  the  prepared  gelatin  or  agar-agar  from  a  local 
hospital  laboratoiy  or  board  of  health,  or  order  from  a  regular  dealer  in 
such  supplies. 


226 


C;i\IC  BIOLOGY 


plug  the  test  tubes.  To  make  plugs,  tear  a  strip  of  cotton 
about  two  inches  wide  and  as  long  as  needed,  fold  length- 
wise, and  roll  into  a  plug.  Insert  this  not  more  than  half 
an  inch  into  the  test  tube.  Cotton  plugs  are  quite  generally 
used  in  bacteriological  work,  since  they  allow  a  free  circu- 
lation of  air  and  prevent  the  entrance  of  germs.    If  material 


Fig.  105.    Preparing  culture  media 
Photograph  by  the  author 

p  --  ^  ^ 

is  properly  sterilized  and  plugged  with  cotton,  it  will  keep 
indefinitely.  (3)  Do  not  open  the  hot-air  sterilizer  until  the 
temperature  is  down  to  40°  or  45°  C.  It  is  preferable  to  leave 
the  dishes  undisturbed  in  the  sterilizer  until  used. 

Before  planting  (inoculating)  your  culture  media  with 
bacteria  observe  the  following: 

Unless  otherwise  directed,  always  inoculate  media  with 
platinum  loop  or  needle.  (1)  Heat  the  wire  in  the  flame 
just  before  and  immediately  after  using.    (2)  Avoid  having 


BACTEKIA 


227 


currents  of  air  in  the  room.  (3)  Upon  opening  a  culture 
medium  for  inoculation,  pass  the  mouth  of  the  tube  through 
the  flame  (flaming)  ;  if  it  has  stood  for  some  time,  flame  the 
cotton  before  opening  the  tube.  (4)  Never  allow  the  tube 
end  of  a  plug  to  come  in  contact  with  anything  while  re- 
moved from  the  tube.  (5)  If  a  plate  culture  is  to  be  made, 
melt  the  gelatin  in  a  test  tube  (placed 
in  warm  water)  and  pour  into  a  ster- 
ile Petri  dish.  If  Petri  dishes  are  not 
available,  test  tubes  may  be  substi- 
tuted, provided  the  gelatin  in  them 
is  allowed  to  cool  Avhile  they  are  lying 
in  a  nearly  horizontal  position.  (6)  In- 
oculation should  not  take  place  before 
the  gelatin  hardens,  unless  germs  from 
a  liquid  are  to  be  grown.  In  this  case 
the  gelatin  is  inoculated  in  the  test 
tube  and  then  poured  into  the  Petri 
dish.  (7)  Unless  otherwise  directed, 
all  cultures  that  have  been  inoculated 
should  be  kept  in  the  dark,  or  in  dif- 
fused light  and  at  room  temperature. 
(8)  If  possible,  duplicate  each  experi- 
ment, using  both  potato  and  gelatin 
media.  Note  appearance  of  growth  in 
each  case.  Label  and  keep  careful  records  of  each  experi- 
ment. (9)  After  your  experiments  are  finished,  do  not  allow 
the  media  to  dry;  place  all  dishes  in  water  and  boil  for 
fifteen  or  twenty  minutes  before  cleaning  them. 

Experiments  for  bacteria  of  the  air.^  (1)  Expose  a  Petri 
dish  of  gelatin  for  five  minutes  in  the  laboratory  before  the 
class  enters.    (2)  Expose  another  for  the  same  length  of  time 

1  Each  member,  or  group  of  members,  of  the  class  should  perform  one  or 
more  of  these  experiments. 


Fig.  106.    Exposing 
dishes 


Petri 


Photograph  by  the  author 


228  CIVIC  BIOLOGY 

in  the  same  room  just  after  the  class  has  left.  (3)  Expose  a 
Petri  dish  of  gelatin  in  a  room  for  five  minutes  immediately 
after  wiping  up  the  dust  Avith  a  dry  cloth  or  after  using  a 
feather  duster.  Compare  this  plate  with  one  that  was  exposed 
for  the  same  length  of  time  in  a  room  immediately  after  it 
had  been  dusted  with  a  damp  cloth.  (4)  Expose  a  plate  in 
a  living  room  for  five  minutes  and  compare  with  the  air  in 
the  yard.  (5)  Compare  the  number  of  bacteria  in  the  air 
upon  the  ground  with  that  of  the  first  and  fourth  stories  of 
the  same  building.  Is  it  true  that  a  child  breathes  less  pure 
air  than  a  man  ?  Is  it  more  desirable  to  sleep  upstairs,  as 
far  as  air  is  concerned  ?  (6)  Expose  a  plate  of  gelatin  in  a 
busy  street  before  and  after  it  has  been  sprmkled,  or  before 
and  after  a  rain.  (7)  C'ompare  the  number  of  bacteria  in  a 
well-cleaned  street  with  the  number  in  one  that  is  not  cleaned. 
What  do  you  think  of  the  system  that  cities  are  using  for 
flushing  their  streets  ?  (8)  Compare  as  to  number  t)f  bacte- 
ria the  au'  before  and  after  a  snowstorm  or  rainstorm.  Inocu- 
late plates  with  rahi  or  fresh  snow.  Keep  these  experiments  in 
a  drawer  in  the  laboratory.  In  a  day  or  so  count  the  colonies 
of  bacteria  and  record  results.  (9)  Sweeten  and  cook  fruit, 
such  as  apples,  in  a  test  tube.  Plug  with  cotton.  Does 
canned  fruit  keep  if  air  is  present  and  bacteria  are  excluded  ? 
(10)  Discuss  the  desirability  of  having  children's  playgrounds 
upon  the  roofs  hi  large  cities. 

Experiments  for  bacteria  of  water.  (1)  Make  a  culture  of 
water  from  a  stream  (dip  your  platinum  loop  three  times) 
and  compare  with  the  same  amount  of  water  from  the  reser- 
voirs and  lakes  of  the  locality.  (2)  Compare  the  water  above 
and  below  the  point  where  the  sewage  is  emptied.  (3)  Com- 
pare the  different  drinking  waters  of  the  locality.  (4)  Make 
cultures  of  water  that  is  rich  in  organic  debris  and  compare 
with  the  same  water  that  has  been  boiled  for  fifteen  minutes. 
(5)  Filter  some  of  the  water  used  in  the  above  experiment 


JLV(TERIA 


229 


through  several  inches  (twelve  or  fifteen)  of  clean  sand.  Is 
a  sand  filter  effective  ?  (6)  Make  cultures  of  milk.  How 
does  fresh  milk  compare  in  the  number  of  its  bacteria  with 
that  which  has  stood  for  some  time  ?  (7)  What  is  meant  by 
Pasteurizing  milk  ?  If  possible,  visit  a  milk  station  where 
milk  for  babies   is   sold.    What   measures   render   it   safe  ? 


Fig.  107.    Inoculating  gelatin  tubes  with  platinum  loop 
Note  the  way  in  which  cotton  plugs  are  held  between  the  fingerf 


Additional  experiments.  (1)  Scrape  the  surface  of  a  silver 
coin  with  a  sterile  knife  and  make  a  plate  culture.  Compare 
with  cultures  made  from  copper  coins  and  paper  money.  No 
paper  money  is  used  in  the  Hawaiian  Islands  because  of  the 
danger  of  transmitting  disease.  (2)  Make  plate  cultures  from 
the  surface  of  a  pencil  that  a  child  has  used  for  some  time ; 
from  the  edge  of  a  common  drinking  cup,  door  handle,  straps 


230  CIVIC  BIOLOGY 

in  a  street  car.  (3)  Make  a  culture  from  a  dishcloth  that  is 
washed  and  boiled  once  a  day,  and  from  one  that  is  not. 
(4)  Compare  the  number  of  bacteria  in  rancid  and  fresh 
butter.  (5)  Allow  a  fly  to  walk  across  a  plate  of  sterile 
gelatin  ;  record  results.  (6)  Make  a  stab  culture  by  running 
a  straight  platinum  wire,  with  germs  upon  it,  down  through 
several  inches  of  sterile  gelatm  in  a  tube.  Upon  removing  the 
wire  the  gelatin  closes  around  the  germs  left  in  its  track,  and 
serves  to  cut  off  the  air  supply  except  at  the  surface.  Do  you 
find  three  classes  of  bacteria  growing  in  the  culture  ? 

The  excretions  of  bacteria  render  the  most  favorable  medium 
unfavorable.  In  general,  bacteria  do  not  grow  as  well  upon  acid 
as  upon  slightly  alkaline  media.  (7)  Make  a  culture  from  the 
dust  of  a  dark  corner  of  a  room;  from  a  surface  in  diffused 
light;  from  one  in  bright  sunlight.  Can  you  think  of  more 
favorable  conditions  for  the  growth  of  bacteria  than  that 
offered  by  the  mouth  ?  How  can  you  keep  your  teeth  from 
being  destroyed  by  them  ?  (8)  Inoculate  a  plate  with  clean- 
ing of  a  finger  nail,  dandruff,  single  human  hair,  cat  hair. 
(9)  Breathe  into  a  gelatin  tube  without  touching  the  lips  to 
the  glass;  make  a  plate  culture.  Can  the  breath  carry  bac- 
teria ?  (10)  Make  a  plate  culture  of  some  of  the  substance 
that  has  gathered  upon  the  back  of  the  teeth.  (11)  A  bacillus 
has  a  characteristic  growth  upon  a  culture  medium.  From  the 
appearance  of  the  colonies  do  your  experiments  show  that  you 
have  grown  different  species  of  bacteria  ?  Can  you  see  that 
by  selecting  a  species  of  bacteria  and  hioculating  a  fresh  cul- 
ture with  it,  and  then  from  it  again  selecting  and  inoculat- 
ing a  fresh  medium,  you  would  soon  obtain  a  medium  with  a 
''pure  culture"  of  that  species  of  bacteria?  (12)  Can  you 
now  explain  the  need  of  such  rules  and  precautions  as  are 
given  in  the  early  part  of  this  chapter  ? 


CHAPTER  XXIII 

CON^TROL  OF  BACTERIAL  DISEASES 

Aristotle  (384-322  b.c.)  instructed  Alexander  the  Great  to  have  his  sol- 
diers boil  their  water  in  order  to  prevent  epidemics  of  disease  in  camps. 
JPossibly  to  this  bit  of  practical  biology  Alexander  ovv^es  his  conquest  of 
the  world. 

Advertendum  etiam,  siqua  erunt  loca  palustria,  et  propter  easdem  causas, 
et  quod  (arescunt)  crescunt  animalia  quaedam  minuta,  quae  non  possunt 
oculi  consequi,  et  per  aera  intus  in  corpore  per  os  ac  nares  perveniunt  atque 
efficiunt  difficilis  morbos.i  —  Varro  (b.c.  116-27),  "De  Re  Rustica,"  Lib.  I, 
11-12  (Keil,  145) 

Already  in  his  studies  on  silkworms,  Pasteur's  first  experience  in  the 
domain  of  disease,  the  dawn  of  a  new  era  in  the  contest  of  man  with  con- 
tagion opens  up  before  him.  He  says:  "II  est  au  pouvoir  de  I'homme 
de  faire  disparaitre  de  la  surface  du  globe  les  maladies  parasitaires,  si, 
comme  c'est  ma  conviction,  la  doctrine  de  la  g^n^ration  spontan^e  est  une 
chim6re."2  —  Frankland,  ''Life  of  Pasteur,"  p.  123 

Bacteria  and  disease.  The  majority  of  bacteria  are  harm- 
less or  beneficial.  A  few  are  venomous,  as  are  a  few  species 
of  snakes,  fishes,  trees,  or  mushrooms.  The  venomous  bac- 
teria strike  plants,  animals,  and  man  just  as  really  as  do  lead 
bullets,  and  wound  and  kill  in  essentially  similar  ways.  The 
notion  is  current  that  bullets  hit  the  fittest,  while  bacteria 
seek  out  the  unfit,  but  there  is  not  much  ground  for  this 

1  ''  One  should  be  on  guard,  if  there  should  be  any  swampy. places,  both 
for  the  same  reasons  and  because  there  grow  certain  minute  animals,  which 
the  eyes  cannot  perceive,  and  which,  permeating  the  air,  enter  the  body 
through  mouth  and  nostrils  and  cause  serious  diseases." — Professor  S.  F. 
Dunn,  University  of  Oregon,  Translator 

2  "It  is  within  the  power  of  man  to  cause  to  disappear  from  the  surface 
of  the  globe  the  parasitic  diseases,  if,  as  is  my  conviction,  the  doctrine  of 
spontaneous' generation  is  a  chimera." 

231 


1900  1901  1902  1903  1904  1905  1906  1907  1908  1909  1910  1911  1912 


Fig.  108.    Death  rate  per  100,000  population  in  the  registration  area 
of  the  United  States 

From  the  Census,  Mortality  Statistics,  1912 


232 


CONTROL  OF  BACTERIAL  DISEASES  233 

idea.i  Ignorance  aside,  there  is  no  more  reason  for  allowing 
ourselves  to  be  bitten  by  bacteria  than  by  rattlesnakes. 
About  two  people  die  from  snake  venom  annually  in  the 
United  States;  20,000  die  yearly  in  India  from  snake  bite, 
because  cobras  are  accorded  superstitious  protection.  We 
religiously  preserve  our  bacteria,  with  the  filth  in  which  they 
thrive  and  the  flies  that  distribute  them ;  the  Hindus,  their 
relatively  harndess  snakes. 

A  few  of  the  more  familiar  germs,  with  the  disease  and 
death  they  are  causing,  are  presented  in  the  table  on  page  234. 
When  we  all  know  how  to  kill  and  avoid  these  bacteria,  as 
well  as  we  know  how  to  deal  with  rattlesnakes,  we  may  be 
as  free  from  them  as  we  are  from  the  snakes.  All  must 
know  and  each  must  do  his  part,  for  one  ignorant  person 
can  scatter  bacteria  by  the  million  from  j\Iaine  to  California. 

The  table  is  by  no  means  complete.  In  the  next  chapter  we  shall 
study  a  similar  list  of  diseases  caused  by  parasites  of  animal  origin. 
There  is  another  list,  known  to  be  infections,  —  smallpox,  yellow 
fever,  scarlet  fever,  measles,  spotted  fever,  and  foot-and-mouth  disease, 
—  the  specific  causes  of  which  have  baffled  all  attempts  to  discover. 
Still  another  class  of  ailments,  noninfectious,  chronic  and  organic, — 
of  the  heart  and  arteries,  brain  and  kidneys,  —  of  heavy  and  increasing- 
fatality,  may  have  to  do  with  organs  weakened  by  parasitic  attack. 
Finally,  we  have  no  statistics  of  the  number  of  the  wounded,  the 
weakened  or  crippled,  and  the  number  of  minor  ailments,  very  numer- 
ous and  of  constant  occurrence,  that  impose  their  burdens  of  sheer 
misery  —  the  millions  of  cases  of  rheumatism,  tonsillitis,  boils,  felons, 
carious  teeth  and  toothache,  indigestions,  diarrheas  and  dysenteries, 
and  "colds,"  most  wretched  of  all,  probably  not  less  than  200,000,000 
of  them  a  year.  When  we  add  to  all  this  the  bacterial  diseases  of 
animals  (hog  and  fowl  choleras,  bovine,  avian,  and  other  tuberculoses 
and  pneumonias,  white   diarrhea   of  chicks   and   foul   brood   of  bees, 

1  "  Neither  regularity  of  life  nor  bodily  strength  was  any  preservation 
against  it.  The  strong  and  the  weak  were  equally  struck  down  ;  and  death 
spared  not  those  of  whom  care  was  taken,  any  more  than  the  poor,  desti- 
tute of  all  help.",  (The  fleas  of  that  time  bit  all  alike.)  — Gasqiet,  "The 
Black  Death,"  p.  12 


234 


CIVIC  BIOLOCY 


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CONTROL  OF  BACTERIAL  DISEASES  235 

anthrax  and  glanders,  and  many  others)  and  the  long  list  of  bacterial 
diseases  of  plants,  already  briefly  considered,  we  begin  to  realize  that 
the  very  edge  of  the  struggle  for  existence  lies  between  mankind  and 
the  bacteria. 

The  three  questions.  The  following  questions  apply  to  the 
parasitic  diseases  —  bacterial,  protozoan,  vermian,  and  all  the 
rest.  When  Pasteur  was  "wasting  his  time"  disproving 
spontaneous  generation,  one  of  his  friends  wrote:  "He  makes 
me  uneasy,  he  does  not  recognize  the  limits  of  science,  he 
only  loves  insoluble  problems."  Now  that  we  know  that 
''  la  gejneration  spontanee  est  une  cMmere^^  the  problem  of  the 
control  of  disease  becomes  the  comparatively  easy  one  of 
preventing  the  spread  of  the  living  germs  from  the  sick  to 
the  well.  In  every  case  of  contagion  or  infection  the  germs 
escape  alive  from  the  body  of  the  sick,  are  carried  to  the 
well,  and  gain  entrance.  Therefore  the  three  fundamental 
questions  are: 

1.  How  do  the  germs  of  each  disease  escape  from  the 
body  of  the  patient? 

2.  How  is  each  kind  of  germ  carried  ? 

3.  How  does  each  kind  of  germ  gain  access  to  the  body? 
Paths  of  escape.     Parasitic  germs  of  the  lungs,  nostrils, 

throat,  or  mouth  (of  diphtheria,  tonsillitis,  pneumonia,  tuber- 
culosis, rhinitis,  bronchitis,  and  influenza,  as  well  as  stomach 
and  intestinal  diseases  that  involve  vomiting — typhoid  fever, 
enteritis,  and  cholera)  escape  with  any  discharges  from  mouth 
or  nose.  Careless  coughing  and  sneezing  may  scatter  the 
germs  over  anything  or  anybody  within  a  distance  of  about 
six  feet.  Spitting  in  any  public  place  is  an  abomination,  and 
laws  against  it  should  be  rigidly  enforced  in  the  interests 
of  public  education  as  well  as  health. 

Bacteria  from  the  digestive  and  renal-reproductive  organs 
pass  out  with  the  dejecta  —  dysentery,  choleras,  typhoid. 
Typhoid  bacilli  have   also,  been  found  in  the  perspiration. 


286 


CIVIC  BIOLOGY 


Germs  circulating  in  the  blood  are  usually  drawn  off  by 
blood-sucking  insects,  ticks,  or  mites  ;  malaria  and  yellow 
fever,  by  mosquitoes  ;  typhus  fever,  by  bod}'  lice  (and  per- 
haps by  fleas  and  bedbugs)  ;  plague,  by  fleas  (possibly  also 
leprosy) ;  typhoid,  by  bedbugs  ;  Texas  fever  and  spotted 
fever,  by  ticks;    infantile  paralysis  (?)  and  anthrax,  b}^  the 


Micrococci 


Bacilli 


Spirilla 


Grippe 


Diphtheria 


Fig.  109.     Pathogenic   bacteria   modeled   to  scale   in  plasticene   (niicra  = 
centimeters),  magnification  of  models  being  10,000  diameters 

A  suggestion  for  a  laboratory  collection.    Mount  in  insect  cases  under  glass. 
Photograph  by  the  author 

stable  fly ;  and  sleeping  sickness,  by  one  of  the  tsetse  flies. 
Diseases  marked  by  lesions  of  the  skin — measles,  scarlet  fever, 
smallpox,  and  probably  dandruff  and  eczema  —  may  escape 
with  the  scales  of  cuticle  or  the  contents  of  blisters  or  sores. 
How  living  disease  bacteria  are  carried.  The  greatest  barrier 
to  the  learning  of  truth  is  apt  to  be  a  firm  belief  of  an  error. 
No  set  of  ideas  has  cost  the  world  more  misery,  suffering, 
and  loss  than  false  notions,  prejudices,  and  superstitions  re- 
garding the  transmission  of  diseases.    First  they  were  carried 


CONTROL  OF  BACTERIAL  DLSEASES  237 

by  angry  gods,  demons,  and  witches ;  next,  by  the  air  as 
miasms  and  effluvia ;  then,  by  fomites  m  dust  of  clothing  or 
merchandise ;  and,  finally,  we  have  come  down  to  the  sure 
evidence  of  science  that  contact  infection,  chiefly  by  the 
hands,  accounts  for  almost  all  the  spread  of  common  diseases, 
and  insects,  by  contact  or  inoculation,  for  most  of  the  rest. 

Air  not  an  important  carrier.  Just  now  the  air  is  rapidly 
losing  all  its  terrors,  smallpox  being  the  only  disease  which 
may  possibly,  though  not  probably,  be  carried  from  house  to 
house  by  this  agency.  (This  does  not  mean  that  insects  that 
fly  may  not  transmit  many  infections  by  contact.)  Chapin 
puts  the  case  carefully  and  sensibly  as  follows: 

Only  a  few  authorities  now  assert  that  disease  is  carried  by  the 
atmosphere  outside  of  dwellings,  and  this  assertion  is  made  only  in 
regard  to  smallpox.  .  .  .  Infection  by  air,  if  it  does  take  place,  as  is 
commonly  believed,  is  so  difficult  to  avoid  or  guard  against,  and  so 
universal  in  its  action,  that  it  discourages  effort  to  avoid  other  sources 
of  danger.  If  the  sick-room  is  filled  with  floating  contagium,  of  what 
use  is  it  to  make  much  of  an  effort  to  guard  against  contact  infection? 
If  it  should  prove,  as  I  firmly  believe,  that  contact  infection  is  the  chief 
way  in  which  the  contagious  diseases  spread,  an  exaggerated  idea  of 
the  importance  of  air-borne  infection  is  most  mischievous.  It  is  impos- 
sible, as  I  know  from  experience,  to  teach  people  to  avoid  contact  in- 
fection while  they  are  firmly  convinced  that  the  air  is  the  chief  vehicle 
of  infection.  .  .  .  Without  denying  the  possibility  of  such  infection,  it 
may  be  fairly  affirmed  that  there  is  no  evidence  that  it  is  an  appreciable 
factor  in  the  maintenance  of  most  of  our  common  contagious  diseases. 
AYe  are  warranted,  then,  in  discarding  it  as  a  working  hypothesis  and 
devoting  our  chief  attention  to  the  prevention  of  contact  infection.  It 
will  be  a  great  relief  to  most  persons  to  be  freed  from  the  specter  of 
infected  air  —  a  specter  which  has  pursued  the  race  from  the  time  of 
Hippocrates ;  and  we  may  rest  assured  that  if  people  can  as  a  conse- 
quence be  better  taught  to  practice  strict  personal  cleanliness,  they 
will  be  led  to  do  that  which  will,  more  than  anything  else,  prevent 
aerial  infection  also,  if  that  should  in  the  end  be  proved  to  be  of 
more  importance  than  now  appears.  —  Chapin,  "Sources  and  Modes 
of  Infection,"  p.  268  ff. 


238  CIVIC  BIOLOGY 

Even  the  air  of  the  sick-room  has  no  dangers  if  modem 
methods  for  bacteriological  cleanliness  are  strictly  observed — 
that  is,  if  all  waste  matters  or  discharges  go  straight  from 
the  patient  into  the  fire  or  sterilizer,  and  if  the  rubber  gloves 
with  which  all  handling  of  the  patient  is  done  are  disin- 
fected immediately  after  using.  Except  by  the  cough  spray 
a  bacterium  cannot  leave  a  moist  surface,  and  by  the  above 
precautions  no  living  germs  can  become  dry  and  so  enter 
the  dust  of  the  room. 

Fomites.  "  Persons  and  not  things  transmit  diseases." 
This  slogan  is  coming  more  and  more  to  dominate  the  whole 
.field.  Ships,  in  numbers,  have  been  sunk,  cargoes  and  all, 
to  insure  against  purely  imagmary  fomites.  No  sharp  line 
can  be  drawn  between  infection  by  contact  and  infection 
by  fomites.  Contact  infection  implies  the  more  immediate 
transfer  of  germs,  as  in  shaking  hands,  exchanging  pipes, 
swapping  gum,  using  the  same  drinking  cup  or  towel,  inter- 
changing dishes  at  successive  meals,  touching  foods,  candies, 
fruits,  etc.  with  unwashed  hands ;  while  the  theory  of  fomites 
implies  infection  by  germs  carried  alive  and  virulent  in  cloth- 
ing, merchandise,  baggage,  and  mail  matter  for  long  distances 
and  during  considerable  periods  of  weeks  or  even  years.  As 
we  shall  see  in  the  next  paragraph,  when  we  begin  to  pay 
attention  to  them,  there  are  so  many  ways  by  which  bac- 
teria are  carried  fresh  and  green  from  mouth  to  mouth,  by 
direct  or  indirect  contacts  (and  not  only  from  mouth  to 
mouth  but  from  dejecta  to  mouth),  that  it  is  sheer  dis- 
honesty to  crowd  our  own  responsibilities  for  really  inex- 
cusable contacts  over  onto  the  theory  of  fomites.  If  common 
notions  of  fomites  were  true,  we  should  have  to  arm  our 
postal  mail  clerks  with  fumigator  masks  and  rubber  gloves 
or  bury  the  whole  force  every  night.  As  a  matter  of  fact, 
bank  tellers,  handling  "  dirty  money "  all  the  time,  mail 
clerks,  handling  letters  sealed  and  stamped  in  everybody's 


CONTROL  OF  BACTEEIAL  DISEASES  239 

saliva,  second-hand  clothing  dealers,  and  even  rag  sorters, 
all  live  in  average  freedom  from  infections.  Doty's  testi- 
mony on  this  point  is  as  follows: 

The  author  has  .carefully  investigated  the  influence  of  money  as  a 
means  of  infection.  The  results  show  that  those  who  are  constantly 
handling  money,  such  as  bank  officials,  do  not  contract  infectious  dis- 
eases any  oftener  than  others.  The  Treasury  Department  at  Washing- 
ton furnishes  exceedingly  valuable  information  on  this  subject.  Here 
large  quantities  of  filthy  and  offensive  paper  money  are  being  constantly 
handled  and  rehandled  prior  to  destruction,  and  not  the  slightest  evi- 
dence has  been  presented  at  that  place  to  show  that  infectious  diseases 
are  transmitted  by  this  material.  Than  this,  no  more  important  or  con- 
clusive evidence  on  this  subject  can  be  presented. —  Doty,  *' Prevention 
of  Infectious  Diseases,"  p.  10 

Even  epidemics  in  schools  —  of  measles,  diphtheria,  and  scarlet  fever 
—  have  been  found  by  the  medical  examiners  of  New  York  City  to  be 
caused  by  mild  or  incipient  cases  and  by  unsuspected  "carriers  "  —  that 
is,  by  contacts  of  persons  and  not  of  things. 

Terminal  disinfection  (fumigation  or  disinfection  at  termination  of  a 
disease  or  of  quarantine)  was  abandoned  in  Providence  in  1905,  "except 
in  those  very  few  instances  in  which  the  family  was  willing  to  wait  for 
two  successive  negative  throat  and  nose  cultures  from  each  of  its  mem- 
bers," the  idea  being  that  it  was  a  waste  of  public  money  to  disinfect 
rooms  while  members  of  the  family  were  carrying  living  diphtheria 
germs,  and  there  has  been  no  marked  increase  of  recurrent  cases.  "The 
New  York  City  Health  Department  has  given  up  fumigation  after  cases 
of  infectious  disease,  as  a  costly  procedure,  the  inutility  of  which  has 
been  well  established."  ^  A  more  conservative  opinion  is  expressed  by 
an  eminent  authority  as  follows  :  "  Though  the  results  obtained  in  some 
cities  since  abandonment  of  terminal  disinfection  after  certain  diseases 
seem  to  show  that  heretofore  much  useless  disinfection  has  been  done, 
it  is  not  felt  that  the  evidence  thus  far  adduced  fully  justifies  its  dis- 
continuance." ^  The  idea  underlying  this  j^osition  is  that  if  terminal 
disinfection  saves  even  a  few  infections,  it  should  not  be  entirely  aban- 
doned. The  above  is  sufficient  to  show  that  this  important  matter  is 
still  an  open  problem ;  for  the  best  light  upon  which  we  should  consult 

1  American  Journal  of  Public  Health,  Vol.  I  (1915),  p.  166. 

2  H.  S.  Hasseltine,  United  States  Public  Health  Reports  (July,  1915), 
p.  2060. 


240  CIVIC  BIOLOGY 

our  local  health  authorities  (when  possible)  and  the  best  current  health 
literature.  All  are  agreed  that  in  case  of  gross  uncleanliness  or  of  new, 
rare,  and  exceptional  infections,  the  means  of  transmission  of  which  may 
not  be  known,  terminal  disinfection  is  advisable.  It  may  take  years,  or 
even  centuries,  of  hard  work,  but  nothing  can  ever  take  the  place  of 
exact  knowledge  of  the  definite  means  by  which  each  parasitic  germ  is 
harbored  or  transmitted.  Knowing  this,  we  now  exterminate  the  guilty 
mosquito  instead  of  sinking  the  ship  to  prevent  spread  of  yellow  fever, 
and  we  pay  attention  to  the  rats  and  fleas  in  case  of  plague  instead  of 
burning  the  village,  inhabitants  and  all. 

Contact  infection.  It  was  a  lesson,  never  to  be  forgotten, 
when  his  family  physician  once  confessed  to  the  writer  that 
he  had  caused  the  death  of  a  young  mother  by  failing  to 
scrub  the  little-finger  edges  of  his  hands  carefully  enough. 
Upon  such  honesty  as  this  we  can  depend  for  progress  of 
both  science  and  practice.  Could  we  be  as  honest  with  our 
own  hands  for  one  day,  we  might  eacli  learn  a  lesson  of  life- 
long value  to  our  own  ideas  of  rational  cleanliness.  Suppose 
we  mark  with  red  ink  every  spot  on  fingers  or  hands  moist- 
ened by  saliva  or  mucous  secretions  from  the  nose,  and  with 
black  ink  all  areas  soiled  by  contacts  with  things  which  it 
would  be  utterly  disgusting  or  dangerous  to  put  into  the 
mouth  —  the  fly  we  crush,  the  cat  we  touch  (that  has  licked 
her  own  saliva  over  her  fur),  the  dead  mouse  we  have  taken 
from  a  trap,  the  pus  from  a  pimple  or  sore,  and  so  down 
the  list.  If  we  did  this  for  half  a  day  even,  could  we  ever 
again  go  to  the  table  without  obeying  the  scriptural  injunc- 
tion to  wash  the  hands  before  breakhig  bread  ?  And  we 
would  not  be  content  with  ceremonial  touclnng  of  water, 
but  Avould  wish  to  scrub  them  with  soap  until  all  the  ink 
spots  were  off.  If  such  definite  instruction  were  universal, 
we  might  not  have  examples  like  the  following; 

Spread  of  gonococcus  infections,  persistent  and  impossible  to  prevent 
or  trace,  in  the  New  York  City  Babies*  Hospital,  uncontrolled  for  sev- 
eral years  by  laborious  disinfection  of  buildings  and  equipment  (after 


CONTROL  OF  BACTERIAL  DISEASES  241 

finally  discovering  that  the  same  night  nurse  tended  the  infected  cases 
and  new  infections  in  a  distant  ward)  ceased  completely  when  tlie 
nurses  began  disinfecting  their  hands  after  attending  each  case. — 
Holt,  New  York  Medical  Journal,  A'ol.  LXXXI  (1905),  p.  521 

Men  detailed  as  hospital  orderlies  were,  after  they  had  performed 
the  duty  of  emptying  bedpans,  seen  to  go  directly  to  their  meals 
without  washing  their  hands,  and  even  to  distribute  food  to  their 
comrades.^  —  Chapin,  p.  120 

Thus,  at  one  of  the  finest  hospitals  in  this  country,  with  separate 
wards  for  scarlet  fever  and  diphtheria,  a  considerable  number  of  cases 
have  arisen  in  the  general  wards.  The  germs  were  supposed  to  be  air- 
borne, as  it  M^as  said  there  was  no  other  possible  avenue  of  infection. 
AVhen  I  saw  the  head  nurse  lick  her  finger  to  facilitate  turning  the  bed- 
side charts  of  diphtheria  patients,  I  suspected  that  the  princii)les  of 
medical  asepsis  had  not  been  entirely  mastered.  —  Chapix,  p.  105 

.  The  superintendent  of  another  hospital  invited  another  visitor  and 
myself  to  eat  ice  cream  from  the  same  spoon  with  himself,  which  spoon 
was  then  replaced  in  the  freezer  which  w as  to  supply  the  wards.  I  Mas 
most  of  all  impressed  with  the  fact  that  at  the  International  Congress  on 
Tuberculosis  in  1908  a  large  number  of  the  readers  of  papers  moistened 
their  fingers  with  their  tongues  when  turning  the  pages,  and  in  each  of 
the  sections  only  one  drinking  glass  was  provided  for  all  the  speakers ; 
and  this  continued  for  a  day  or  two  without  protest.  —  Chapix,  \).  1«)5 

The  following  observations  were  made  by  the  autlior 
in  1915. 

1.  Stopped  to  buy  candy  in  order  to  observe  "home  manufacture"; 
saw  elderly  man  molding  nut  drops  lick  off  his  fingers  and  go  on  mold- 
ing.   Threw  candy  away. 

2.  Asked  for  pound  of  ]>reserved  ginger  at  a  fine  confectionery  store  ; 
waitress  clawed  it  out  of  tray  with  hands.  Paid  for  it  and  threw  it 
away. 

3.  Called  for  glass  of  milk  at  railway-station  lunch  counter;  swarthy 
foreigner  removed  cap  from  quart  jar,  put  his  dirty  hand  over  bottle, 
turned  it  bottom  up  and  shook  it  violently,  scraped  palm  of  hand  on 
mouth  of  jar,  and  poured  out  the  glass.  He  was  told  to  drink  it 
himself. 

1  From  a  description  of  an  army  typhoid  epidemic. 


242  CIVIC  BIOLOGY 

4.  Observed^  flies  swarming  on  crates  of  raspberries  and  black- 
berries, absolutely  open  and  unprotected  (caught  about  sixty  flies  with 
one  sweep  of  the  hand  over  such  a  crate). 

Carriers  and  contact  with  food.  Typhoid  Mary  was  dis- 
covered by  Soper  in  1906.  She  was  apparently  healthy,  but 
wherever  she  served  as  cook  typhoid  fever  was  sure  to  fol- 
low, and  she  was  found  to  be  alive  with  virulent  typhoid 
bacteria.  She  had  already  caused  several  small  and  at  least 
one  large  epidemic.  From  1907  to  1910  Mary  was  detained 
in  the  isolation  hospital  of  the  New  York  Board  of  Health 
and  then  was  released  upon  her  promise  to  change  her  occu- 
pation. Early  in  1915  an  epidemic  of  25  cases  broke  out 
in  one  of  the  New  York  hospitals,  and  there  in  the  kitchen, 
under  an  assumed  name,  was  found  Typhoid  Mary. 

About  4  per  cent  of  those  who  recover  from  the  disease 
remain  as  typhoid  carriers,  either  continuously  or  intermit- 
tently, and  some  may  not  even  know  that  they  have  ever 
had  typhoid  at  all.  For  some  unaccountable  reason  there 
are  about  five  women  carriers  to  one  man.  A  typhoid  epi- 
demic occurred  at  Hanford,  California,  !March,  1914,  the 
study  of  which  by  the  health  officers  proved  most  instruc- 
tive. A  church  dinner,  of  which  150  partook,  resulted  in 
93  cases  and  3  deaths.  The  infection  was  traced  to  a  woman 
who  had  cut  the  bread  and  prepared  a  dishpan  of  Spanish 
spaghetti.  She  had  nursed  her  daughter  through  typhoid 
thirty-five  years  before,  but  did  not  know  that  she  herself 
had  ever  had  the  disease.  In  order  to  test  the  matter  a 
dish  of  spaghetti,  not  so  large,  was  similarly  prepared,  and, 
although  baked  much  more  thoroughly  than  that  served  at 
the  dinner  (until  the  top  was  brown,  the  points  on  the  sur- 
face were  charred,  and  the  edges  were  boiling  furiously) 
living  typhoid  bacilli  were  found  within  half  an  inch  of  the 

1  In  a  public  market,  Washington,  D.C.,  July  3,  1916. 


CONTROL  OF  BACTEEIAL  DISEASES  243 

surface  and  at  the  center  of  the  mass  they  were  swarming, 
and  the  temperature  there  was  only  28°  C.  This  proved 
that  "  ordinary  baking  merely  incubates  the  interior  of  these 
masses  of  food."  ^ 

At  a  Gettysburg  soldiers'  reunion  one  of  the  men  "  not  feeling  very 
well"  was  assigned  mess  duty.  As  a  consequence  (probably  of  his 
handling  the  bread)  fifty-five  of  the  company  developed  typhoid. 

Naturally  extreme  danger  attaches  to  contact  infection  of  foods  in 
which  bacteria  may  multiply  —  lobster,  shellfish;  cooked  meats,  and  es- 
pecially milk.  Formerly  epidemics  following  the  eating  of  these  things 
were  explained  on  the  theory  of  "ptomaine  poisoning" — that  is,  that 
poisons  (ptomaines)  were  formed  by  bacterial  growth  in  the  substance, 
which  were  not  destroyed  by  heat.  Jordan  says  of  this  :  "  Many  of  the 
epidemics  of  'meat  poisoning '  etc.  are  now  known  to  be  due  to  infection 
with  a  specific  microorganism  rather  than  to  the  action  of  a  formed 
poison."  2  Milk  is  a  most  favorable  culture  medium  for  bacterial  growth, 
and  naturally  many  epidemics  are  traced  to  it.  Chapin  gives  the  follow- 
ing figures :  315  outbreaks  of  typhoid,  125  of  scarlet  fever,  51  of  diph- 
theria, and  7  of  tonsillitis  (epidemic  sore  throat).  Immediate  report  to 
the  board  of  health  of  the  milk  route  on  which  a  case  of  illness  occurs 
makes  it  possible  to  nip  many  an  epidemic  in  the  bud,  a  visit  to  the  dairy 
generally  revealing  the  source  of  the  infection. 

Recent  outbreaks  of  typhoid  on  two  milk  routes  in  Hartford,  Con- 
necticut,— 12  cases  in  September,  1914,  and  34  cases  in  November, — 
were  traced  to  the  same  carrier,  an  occasional  milker,  who  had  moved 
from  one  dairy  to  the  other. 

All  the  typhoid,  21  cases,  in  a  Minnesota  town  for  five  years  was 
traced  to  one  carrier  in  a  dairy.  ^ 

An  epidemic  of  diphtheria  in  Lincoln,  Nebraska,  of  110  cases  and 
2  deaths  (97  received  antitoxin  promptly,  and  none  of  these  died)  was 
traced  to  a  diphtheretic  "  sore  throat "  of  a  milker.  The  money  cost  to 
the  community  of  this  '*  trifling  sore  throat "  is  estimated  at  |10,000,  in 
addition  to  the  suffering,  labor  of  nursing,  and  the  2  deaths.* 

^  Sawyer,  Journal  of  the  American  Medical  Association,  1914,  p.  1537. 
2  Jordan,  General  Bacteriology,  p.  101. 

8  H.W.  Hill,  American  Journal  of  Public  Health,  Vol.  IV  (1914),  p.  667. 
4  Wait,  '^  Report   of   Milk-borne   Epidemic   of   Diphtheria,"  American 
Journal  of  Public  Health,  Vol.  IV  (1914),  p.  418. 


244  CIVIC  BIOLOGY 

Clean  milk.  For  many,  possibly  for  all,  coiimmnities  uo  better  health- 
conservation  work  could  be  undertaken  than  solving,  each  member  of 
the  class  for  his  own  home  and  the  whole  class  for  the  home  commu- 
nity, the  problem  of  safe  and  clean  milk.  Milk  is  safe  when  all  disease 
germs  are  kept  out  of  it,  and  it  is  clean  when  free  from  filth  of  all  sorts, 
usually  indicated  by  numbers  of  other  bacteria.  As  secreted  by  healthy 
cows,  milk  is  pure,  and  by  observing  hosi)ital-operating-rooin  precau- 
tions it  can  be  kept  so.  ^  Von  Behring's  statement  that  milk  should  not 
-1)6  used  for  infant  feeding  if  it  contains  more  than  1000  bacteria  per 
cubic  centimeter  is  rarely  lived  up  to.  Boston's  standard  of  purity 
(which  Spargo  thinks  is  worse  than  no  standard  at  all)  allows  500,000 
bacteria  per  cubic  centimeter,  and  "  certified  milk  "  may  run  as  high  as 
10,000  bacteria  per  cubic  centimeter.  Secure  copies  of  specifications  for 
local  certified  dairies. '^  If  possible,  have  a  committee  of  the  class,  or 
each  member,  work  up  the  technique  of  making  the  bacterial  count  and 
examine  local  milk  su[)]>lies.* 

We  have  been  too  long  scoring  dairies  according  to  buildings  and 
equipment,  and  nothing  could  be  more  convincing  for  the  truth  of 
Dr.  North's  contention  that  dirty  milk  is  90  per  cent  due  to  dirty  or 
ignorant  dairymen  than  his  demonstration  in  ten  Kelton  dairies.  Ten 
trained  Oxford  dairymen  were  shipped  over  to  Kelton  in  time  to  do  the 
evening  milking  in  ten  of  the  dirtiest  Kelton  dairies,  with  the  result 
shown  on  the  next  page  :  bacteria  in  the  milk  reduced  from  millions 
to  less  than  10,000  per  cubic  centimeter,  in  all  but  Xo.  0,  a  most  in- 
structive exception.  ^ 

Four  things  necessary  to  production  of  clean  milk  : 

1.  Milking  with  dry  hands  into  covered  pails. 

2.  Proper  washing  and  sterilization  of  milking  pails  and  milk  cans. 

3.  Cooling  milk  by  placing  cans  in  tanks  of  cold  water  or  ice  water. 
L  Regular  laboratory  testing  of  milk  for  bacteria,  and  payment 

l>ased  on  the  laboratory  tests. 

Pasteurized  milk.  Dangerous  milk  can  be  made  safe  by  heating  to  (JO^ 
for  twenty  minutes,  and  this  does  not  seriously  injure  its  nutritional 
value.     This  treatment  kills  all  non-spore-forming  disease  germs  of 

^  Kosenau,  The  Milk  Question,  p.  73.  (Tells  how  Mr.  8.  L.  Stewart,  New- 
burgh,  New  York,  produces  milk  free  from  bacteria.) 

2  Rosenau,  Requirements  for  "Certified  Milk,"  pp.  151-160. 

^  Russell  and  Hastings,  Experimental  Dairy  Bacteriology,  p.  122. 

*  North,  "The  Dairyman  versus  the  Dairy,"  American  Journal  of  Publk 
Health,  Vol.  V,  pp.  510^525. 


CONTKOL  OF  BACTERIAL  DISEASES 


245 


Bactehial  Tests  of  Milk  produced  in  Keltox  Dairies 
(Bacteria  per  Cubic  Centimeter) 


Bv  Keltox  Dairymen 

Bv  Oxford  Dairymen 

April  5: 

April  6 : 

1,830,000 

3,300 

1,520,000 

3,100 

4,830,000 

4,600 

4,000,000 

7,000 

1,450,000 

4,100 

3,600,000 

61,0003 

60,0001 

800 

9,0002 

2,600 

70,000 

1,600 

500,000 

5,600 

tuberculosis,  typhoid,  dysentery,  diphtheria,  tonsillitis,  cholera,  and  the 
virus  of  scarlet  fever.  This  does  not  make  the  milk  any  cleaner,  nor  does 
it  kill  the  more  resistant  bacteria,  but  if  it  is  dangerous,  it  renders 
it  safe. 

Flies,  vermin,  house  pets  as  transmitters  of  contact  in- 
fections. After  the  human  hand  coine  other  active  g'erm 
carriers,  and  among  tliese  the  house  fly  probably  stands 
first  not  only  in  transmitting  germs  of  filth  and  disease  to 
foods  but  in  combining  air-carriage  with  contact.  This  prob- 
lem has  been  treated  in  a  previous  chapter.  Roaches  and  rats 
and  mice  should  be  universally  recognized  as  too  filthy  to 
eat  with,  and  should  be  completely  exterminated,  along  with 
the  flies,  from  every  household.  Cats,  on  account  of  their 
often  intimate  contact  with  children,  have  been  responsible 
for  innumerable  infections,  especially  of  diphtheria.  Since 
this  germ  attacks  cats  virulently,  they  assume  the  double  role 
of  irresponsible  patients  and  mechanical  carriers  in  the  family. 


1  This  dairy,  on  April  3,  had  a  count  of  8,000,000. 

2  This  count  was  made  March  30. 

^  Due  to  Keltou  dairymen  raising  dust  by  sweeping  at  milking  time. 


246  CIVIC  BIOLOGY 

Every  case  of  '^  cold "  or  "  sore  throat "  in  a  cat  should  be 
considered  diphtheretic  or  tubercular  until  proved  otherwise. 
Serious  epidemics  of  diphtheria  have  been  traced  to  cats,  and 
these  have  had  to  be  killed  or  rigidly  excluded  from  homes 
before  spread  of  the  disease  could  be  stopped.  Cases  of  scar- 
let fever  are  sometimes  traced  to  cats  as  passive  carriers.^ 
While  dogs  may  act  as  mechanical  carriers  of  bacteria,  and 
are  responsible  for  harboring  several  animal  parasites,  which 
we  shall  have  to  consider  later,  they  are  almost  immune  from 
bacterial  attack. 

Recent  civic  advances  due  to  acceptance  of  contact  infection. 
Public  drinking-cups  and  common  towels  have  vanished  as  if 
by  magic.  Sanitary  regulation  of  dishwashing  and  bed  linen 
in  hotels  and  restaurants,  sanitary  protection  of  drinking- 
straws  and  cleansing  of  glasses  in  soda  fountains,  wrapping 
and  boxing  of  bread,  other  foods,  and  candies,  to  prevent 
contact  in  handling,  liquid  and  individual  soaps,  and  many 
other  items  of  modern  improvement  are  active  steps  in  the 
direction  of  rational  prevention  of  contact  infections.  As 
with  the  dairies,  when  we  all  realize  that  intelligence  in  per- 
sonnel is  of  more  importance  than  equipment,  we  shall  see  to 
it  that  only  the  healthy  and  cleanly  and  those  who  know  are 
allowed  to  work  in  dairies  or  take  care  of  foods  in  markets 
or  eating  houses.  No  man  who  does  not  know  better  than 
to  put  his  bare  hand  over  a  milk  bottle,  or  woman  who 
does  not  know  better  than  to  take  candy  from  a  tray  with 
her  bare  fingers,  has  any  right  to  serve  the  public.  Our  mil- 
lions of  preventable  infections  and  our  more  than  500,000 
deaths  annually  are  the  measure  of  our  need  in  this  direction. 

Resistance,  susceptibility,  and  immunity.  Possibly  every 
American  chestnut   tree  on   the  continent  is   susceptible  — 

1  Caroline  A.  Osborne,  M.D.,  ''The  Cat  a  Neglected  Factor  in  Sanitary- 
Science,"  Pedagogical  Seminary,  1907  ;  also  "The  Cat  and  the  Transmission 
of  Disease,"  Medical  Recorder,  Chicago,  1912. 


CONTROL  OF  BACTERIAL  DISEASES  247 

unable  to  offer  resistance — to  the  fungus  of  bark  disease.  In 
that  case,  unless  some  specimens  can  be  taken  beyond  reach 
of  the  spores,  every  chestnut  tree  in  America  will  be  killed. 
If  immune  trees  can  be  found,  it  may  be  possible  to  propa- 
gate from  them  a  strain  of  immune  trees  and  so  save  the 
species  to  the  continent.  It  is  possible,  though  not  probable, 
that  something  may  be  discovered  which,  injected  into  the  sap 
of  the  tree  or  fed  into  the  tree  from  the  soil,  will  enable  it  to 
resist  the  fungus,  that  is,  give  the  tree  an  artificial  or  acquired 
immunity.  It  is  conceivable  that  we  might  inject  some  of 
the  sap  from  an  immune  tree  into  a  susceptible  tree  —  vacci- 
nate, or  inoculate  —  and  so  immunize  it  and  save  its  life. 

Every  animal  or  plant  offers  some  resistance  to  being  eaten 
alive  by  a  parasite.  Tins  resistance  may  be  natural  or  ac- 
quired ;  it  may  be  mechanical  (skin,  bark,  cuticle,  too  resist- 
ant for  parasites  to  break  through)  or,  as  is  more  common, 
it  may  be  chemical  (some  poisonous,  toxic  substance  is  pro- 
duced that  weakens  or  kills  parasites).  As  a  nation  stung 
by  foreign  attack  begins  to  make  ammunition,  so  cells  of  the 
host  may  be  stimulated  by  the  toxins  of  a  parasite  to  produce 
defensive  substances  —  antitoxins  or  antibodies.  In  this  case 
the  acquired  resistance,  or  immunity,  is  said  to  be  active. 
If  the  defensive  substance,  antitoxin,  is  injected  from  some 
other  person  or  animal,  as  if  a  foreign  nation  sent  in  its  army 
and  ammunition,  the  immunity  conferred  is  said  to  be  pas- 
sive, and  this  is  not  likely  to  last  so  long  as  active  immunity. 
Recovery  from  certain  diseases  (whooping  cough,  measles, 
mumps,  scarlet  fever,  smallpox)  generally  leaves  the  body 
armed  with  acquired  immunity  against  a  second  attack  by  the 
same  germs  —  that  is,  leaves  an  experienced  army  that  can 
prevent  another  invasion.  This,  in  a  true  sense,  is  the  case, 
the  white  blood  corpuscles  (phagocytes)  often  gaining  the 
power  to  eat  the  germs,  probably  alive,  instead  of  being 
eaten  by  them.    The  process  is  not  always  as  simple  as  this. 


248  CIVIC  BIOLOGY 

The  white  corpuscles  may  not  be  able  to  ingest  some  bac- 
teria unless  there  are  certain  substances  in  the  blood  to  help 
them.  These  are  called  opsonins  (Gr.  oyjrcoveQ),  I  prepare  food 
for),  and  their  amount  in  the  blood  as  compared  with  a  nor- 
mal standard  is  known  as  the  opsonic  index.  The  injection  of 
killed  bacteria  of  the  exact  kind  that  are  causing  the  trouble 
(made  with  cultures  taken  from  the  patient  —  autogenous 
bacterins)  often  results  in  a  sharp  rise  in  the  opsonic  index 
and  with  this  a  quick  defeat  of  the  invadmg  germs. 

Great  prejudice  has  existed  against  the  use  of  these  vac- 
cines, antitoxins,  bacterins,  and  serums,  and  one  accident 
attributed  to  them,  perhaps  falsely,  is  often  made  to  out- 
weigh in  popular  prejudice  the  literally  thousands  of  deaths 
caused  by  the  natural  course  of  infections.  Beginning  with 
vaccination,  discovered  by  Jenner,  in  1796,  we  now  have 
safe  and  effective  vaccines,  antitoxins,  bacterins,  and  serums 
for  rabies,  diphtheria,  tetanus  (lockjaw),  pneumonia,  boils, 
pimples,  and  inflammatory  fevers,  cholera,  bubonic  plague, 
bacterial  dysentery,  cerebrospinal  meningitis,  and  typhoid 
fever,  and,  among  animal  diseases,  anthrax,  distemper  of 
dogs,  hog  and  fowl  choleras,  blackleg,  and  tetanus,  with 
many  more  that  are  on  the  way  toward  perfection.  It  is 
claimed  by  some  high  in  authority  that  the  present  great  war 
will  result  in  lengthening  the  average  of  human  life  by  as 
much  as  fifteen  years,  by  breaking  down  apathy  and  ancient 
prejudice  and  demonstrating  the  value  of  modern  bacterio- 
logical science.  Typhoid  has  been  banished  from  our  army 
by  preventive  inoculation.  Let  some  pupil  volunteer  to  look 
up  the  story  of  this  and  report  to  the  class. 

Asepsis,  antisepsis,  germicides,  and  paths  of  entrance  to  the 
body.  Blood  wells  from  a  wound,  carrying  out  the  germs 
that  may  have  entered,  rendering  it  germ-free,  or  aseptic,  and 
then  it  clots  to  seal  it  over.  This  is  nature's  primitive  aseptic 
surgery.     The  saliva  is  somewhat  antiseptic,  and   the  acid 


CONTROL  OF  BACTERIAL  DISEASES  249 

gastric  juice  of  the  stomach  is  strongly  germicidal,  these  bemg 
nature's  provisions  for  turning  the  food  over  to  the  absorp- 
tive organs  germ-free.  Breaks  in  the  skin  and  mucous  mem- 
branes and  the  mouth  are  the  great  channels  of  entrance  for 
germs,  and  the  fact  that  there  are  so  many  preventable  in- 
fections proves,  that  under  modern  conditions  of  life  nature's 
provisions  need  constant  reenforcement.  In  normal  breathing 
through  the  nostrils  the  germs  are  caught  before  they  reach 
the  lungs,  so  that  even  pulmonary  tuberculosis  is  coming 
more  and  more  to  be  considered  a  mouth  infection,  reaching 
the  lungs  either  by  way  of  inflamed  tonsils  or  by  way  of 
stomach,  intestine,  thoracic  duct,  and  circulation. 

When  the  role  of  bacteria  in  causing  disease  was  first  dis- 
covered, chemical  poisons  were  sought  which  might  kill  the 
germs  without  quite  killing  the  patient.  Carbolic  acid  (phe- 
nol), mercuric  chloride  (corrosive  sublimate),  and  formalin 
were  the  germicides  first  used  most  extensively,  and  the  gov- 
ernment standard  of  efficiency,  "  the  phenol  coefficient,"  is 
the  germ-killing  power  of  phenol.  Later  came  the  delicate, 
specific,  exact  antitoxins  and  resistance  serums  that  kill  the 
particular  germ  and  have  no  poisonous  action  on  the  cells 
of  the  body.  Other  nonpoisonous  germicides,  especially  the 
hypochlorites,  from  general  use  in  purification  of  drinking 
water  and  sewage,  are  being  adapted  to  dairy,  home,  and 
personal  use.  Here  oxygen  is  the  active  germicide,  and  the 
end  products  of  the  reaction  are  harmless  calcium  chloride 
in  case  of  hypochlorite  of  lime,  and,  with  sodium  hypo- 
chlorite, sodium  chloride,  or  common  salt.^ 

1  "  Three  grains  of  a  practically  harmless  substance  will  kill  the  myriads 
of  germs  in  a  barrel  of  water.  To  do  the  same  work  with  the  poisonous  cor- 
rosive sublimate  would  require  at  least  one  ounce,  or  of  the  equally  poison- 
ous carbolic  acid  five  pounds  (p.  23).  .  .  .  Hypochlorous  acid  is  one  of  the 
most  powerful  oxidizing  agents  known  to  chemists.  The  'acid  mixture' 
will,  within  a  minute,  kill  spores  which  resist  5  per  cent  solution  of  carbolic 
acid  for  weeks"  (p.  54).  —  Hooker,  Chloride  of  Lime  in  Sanitation,  1013 


250  CIVIC  BIOLOGY 

Keeping  abreast  of  discovery.  Bacteriology  is  a  young 
science,  and  hundreds  of  students  are  pushing  discovery 
forward  so  rapidly  that  we  must  "  step  lively "  to  keep  up. 
Have  committees  of  the  class  invite  members  of  the  state 
and  local  boards  of  health  and  public-spirited  physicians  to 
come  in  and  discuss  their  problems.  Try  to  gain  clear  ideas 
of  just  those  problems  in  dealing  with  which  the  community 
most  needs  to  develop  "  cooperative  good  will,"  and  make 
a  test  of  what  a  biology  class  can  do  to  help.  No  matter 
where  it  is,  or  how  large  or  how  small  it  may  be,  any  com- 
munity that  can,  by  intelligent,  united  effort,  demonstrate 
accomplished  control  of  such  infections  as  tuberculosis,  grippe, 
common  colds,  pneumonia,  diphtheria,  typhoid,  and  summer 
choleras  of  infants,  may  "go  to  the  head";  and  the  class  of 
young  men  and  women  who  help  to  attain  this  result  will 
have  a  story  to  tell  that  the  sick  and  tired  old  world  has 
waited  thousands  of  years  to  hear. 

Problem  summary.  What  do  we  mean  by  "  clean  hands  "  ?  Are  our 
fingers  generally  clean  enough  to  put  into  our  own  mouths  or  into  the 
mouths  of  other  people,  that  is,  to  handle  our  own  food  with  and  that 
of  others  ?  Tests :  Touch  finger  tips,  unwashed  and  washed,  to  agar 
plates,  incubate,  and  compare  growths.  To  determine  how  many  germs 
we  may  collect  on  the  hands  in  a  half-day's  work,  wash  the  hands  with- 
out soap  (cleaning  the  nails  thoroughly)  in  two  liters  of  sterile  water. 
Inoculate  a  plate  with  1  cubic  centimeter,  incubate,  count  colonies,  and 
estimate  total  number.  —  Read  "  Dirty  Hands  and  Typhoid  Fever," 
American  Journal  of  Public  Health,  Vol.  IV  (1914),  p.  141. 

Study  conditions  in  local  stores,  bakeries,  and  candy  shops.  Are 
foods  and  confections  that  go  directly  into  the  mouth  handled  with  the 
bare  hands?  Can  you  devise  practical  ways  and  means  of  doing  away 
with  all  such  handling? 

Look  up  thoroughly  hygiene  of  mouth,  throat,  and  nose,  and  adopt 
a  definite  plan  that  shall  insure  perfectly  sound  teeth,  uninfected 
tonsils  or  nares,  and  absence  of  adenoids.  Arrange  a  campaign  to  see 
that  ordinances  against  spitting  in  public  places  are  obeyed.  Report 
infractions  to  board  of  health. 


CONTROL  OF  BACTERIAL  DISEASES  251 

Let  each  member  of  the  class  work  out  one  of  the  following  problems 
in  detail  and  present  results  to  class :  IIow  would  you  plan  to  take  sole 
care  of  a  case  of  typhoid  (to  insure  against  catching  it  yourself  or 
permitting  it  to  spread  to  others)  ?  of  tuberculosis  ?  of  grippe  ?  of 
pneumonia?  of  diphtheria?  of  dysentery?  of  erysipelas?  of  leprosy? 
of  scarlet  fever?  of  measles?  of  pellagra?  of  smallpox?  (Refer  to 
best  available  manuals  for  trained  nurses.) 

What  precautions  would  you  take  if  you  were  a  typhoid  carrier? 
if  you  were  a  diphtheria  carrier?  if  you  were  infected  with  tubercu- 
losis? if  you  had  the  grippe?  if  you  had  tonsillitis?  if  you  had  a  cold? 
Is  the  Schick  reaction  used  in  your  district  to  test  immunity  to  diph- 
theria? Look  up  use  of  Widal  reaction  in  detection  of  typhoid  carriers. 

Make  out  a  complete  list  of  diseases  of  man  and  other  animals  for 
which  we  have  reliable  antitoxins,  vaccines,  or  bacterins.  Discuss  their 
use  in  your  district  and  get  reports  from  those  who  have  tested  them. 
File  this  list  in  the  laboratory  and  note  changes  and  growth  from 
year  to  year. 

It  is  estimated  that  in  1914  diseases  of  farm  animals  caused  damage 
to  the  amount  of  $212,000,000.  Can  the  class  work  out  plans  of  co6i> 
eration  by  which  any  of  these  diseases  may  be  brought  under  control  ? 

Compare  the  merits,  for  various  purposes,  of  different  disinfectants, 
antiseptics,  and  germicides  on  the  market.  Study  especially  the  home 
and  dairy  use  of  the  hypochlorites.  Get  the  reports  on  all  these  things 
from  the  United  States  Public  Health  Service,  Washington,  D.C. 

Collect  and  discuss  national,  state,  and  local  quarantine  and  health 
laws  and  ordinances. 

Visit  as  many  of  the  local  dairies  as  possible.  Obtain  the  official 
score  cards  from  your  dairy  inspector  and  study  the  scoring  he  has 
given.     Are  the  dairymen  included  in  the  scoring? 

In  the  light  of  all  you  have  learned  about  bacteria,  discuss  the  prob- 
lem of  washing  dishes  properly.  Should  we  banish  the  "  common  dish- 
towel "  along  with  the  "common  roller  towel."  Make  plate  tests  for 
numbers  of  bacteria  in  "  dishcloths,"  in  "  dish-towels,"  in  "  dishwater," 
and  on  the  dishes  after  different  methods  of  washing  and  drying.  How 
do  these  tests  compare  with  thoee  made  on  dishes  after  actually  boiling 
for  five  minutes  in  the  rinsing  water  ?  after  treating  with  hypochlorite 
in  rinsing  water,  without  wiping  ? 

It  is  being  claimed  that  spread  of  infections  in  families,  especially 
of  colds,  grippe,  and  tonsillitis,  might  be  greatly  reduced  by  steriliza- 
tion of  dishes.    Can  the  class  find  a  test  for  this  in  their  own  homes  ? 


$         T3  ^    5    O 


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252 


«  2  c 


CHAPTER  XXIV 

COJ^TROL  OF  ANIMAL  PARASITES 

1.  To  what  is  hookworm  disease  due  ?  Describe  the  worm.  2.  What  are 
the  symptoms  ?  3.  How  is  the  disease  spread  ?  4.  Give  the  life  history  of 
the  hookworm  from  tlie  time  the  egg  is  laid  until  the  worm  is  back  in  the 
intestine.  5.  Can  the  disease  be  cured  ?  Which  is  better,  cure  or  preven- 
tion ?  6.  How  can  it  be  prevented  ?  7.  Suppose  you  had  charge  of  a  hook- 
worm patient,  describe  your  treatment  and  precautions.  8.  What  can 
school  children  do  to  eradicate  the  disease  in  Essex  County  ?  —  From  a 
quiz  given  in  a  Virginia  high  school 

With  this  as  a  part  of  public-school  work  for  boys  antl  girls,  one  might 
be  tempted  to  call  the  disease  a  blessing ;  for  what  else  could  have  brought 
the  old  ''education"  on  such  a  long  journey  toward  connnon  sense?  Of 
course  it  will  not  stop  with  this  particular  subject.  It  will  deal  more  and 
more  with  the  kinds  of  subjects  that  have  to  do  with  healthful  living  here 
and  now.  How  whimsical  Fate  is,  that  we  should  be  mightily  helped  to  the 
right  kind  of  schools  in  the  United  States  by  an  intestinal  parasite  that  poi- 
soned the  Pharaohs!  —  Walter  H.  Page,  "The  Hookworm  and  Civiliza- 
tion,"  The  World's  Work,  Vol.  XXIV  (1912),  pp.  515  ff. 

But  that  the  mosquito  bite  not  only  annoys  but  may  kill,  by  infecting 
the  punctured  tissues  with  the  germs  of  malaria  or  yellow  fever  or  lilariasis, 
three  of  the  most  wide-spread  and  fatal  diseases  of  man,  —  this  alarming 
fact  is  a  matter  which  has  come  to  be  really  recognized  only  recently,  and 
the  general  recognition  of  which  has  given  to  the  practical  study  of  insects 
an  importance  which  years  of  warning  and  protesting  by  economic  ento- 
mologists have  been  wholly  unable  to  do.  ...  In  addition  I  may  simply 
say,  when  in  malarial  regions  avoid  the  bite  of  a  mosquito  as  you  would 
that  of  a  rattlesnake.  One  may  be  quite  as  serious  in  its  results  as  the  other. 
—  Kellogg,  "American  Insects,"  pp.  303,  630 

Importance.  The  world  over,  it  is  quite  within  the  range 
of  possibility  that  animal  parasites  are  sapping  half  the  life- 
blood  and  strength  of  the  human  race,  and  many  other 
plant  and  animal  species  are  similarly  afflicted.  This  one 
parasite,  the  hookworm,  belts  the  world  between  36°  north 

263 


254  CIVIC  BIOLOGY 

latitude  and  30°  south,  influencing,  more  or  less,  the  lives  of 
940,000,000  people  —  more  than  half  the  population  of  the 
globe.  "  In  Porto  Rico  the  disease  has  reduced  the  average 
efficiency  of  the  labor  on  the  coffee  plantations  to  50  per  cent 
of  normal  efficiency,  and  in  some  cases  to  35  per  cent."  ^ 

Theory  of  control.  Precisely  the  same  argument  applies  to 
animal  parasites  as  was  developed  in  the  preceding  chapter 
with  reference  to  parasitic  bacteria.  All  must  know  the 
facts  in  order  that  each  may  be  able  to  do  his  part  for  the 
safety  of  the  whole  community. 

A  case  in  point  is  the  following: 

The  caretaker  of  an  expensive  pheasant  farm  was  recently  observed 
laboriously  twisting  the  gapeworms  out  of  the  windpipes  of  his  young 
pheasants  and  scattering  them  on  the  ground  of  his  breeding  pens. 
They  were  killing  hundreds  of  his  birds,  but  he  did  not  know  the  life 
history  of  the  parasite.  It  would  have  saved  him  time,  labor,  and  worry, 
and  cost  him  nothing,  had  he  simply  wiped  them  on  a  bit  of  newspaper 
and  burned  them. 

It  may  be  easy  to  prevent  outbreaks  of  trichinosis,  hook- 
worms, tapeworms,  malaria,  yellow  fever,  and  all  the  rest, 
as  soon  as  each  one  knows  exactly  what  to  do  to  prevent 
multiplication  and  spread  of  the  organisms. 

Stiles's  argument  in  regard  to  scattering  hookworms  applies 
to  all  infections.^  We  have  the  parasites  concentrated  in  the 
wastes  of  the  patient,  and  we  can  kill  them  by  the  good  old 
Hebrew  "  cleansing  by  fire,"  or  with  chemical  disinfectants 

1  Thus  there  is  a  distinct  loss  of  10  to  20  per  cent  in  the  wages  and  a  cor- 
responding loss  in  crop  returns.  In  some  places  (this  refers  to  our  own 
South)  I  should  estimate  the  loss  at  even  a  higher  percentage,  say  an  aver- 
age of  25  per  cent,  while  in  several  families  which  I  have  examined  I  should 
say  that  uncinariasis  is  reducing  the  laboring  capacity,  hence  the  produc- 
tiveness, of  the  family  to  as  low  as  30  to  40  per  cent,  thus  entailing  a  loss 
of  60  to  70  per  cent.  —  C.  Wardell  Stiles,  "Prevalence  and  Geographical 
Distribution  of  Hookworm  Disease,"  Hygienic  Laboratory  Bulletin  No.  10 
(Washington,  1903),  p.  96  2  sdles,  loc.  cit.,  pp.  93  ff. 


CONTROL  OF  ANIMAL  PARASITES  255 

(chloride  of  lime),  before  they  become  scattered  in  sewage  or 
water  or  in  the  soil,  or  are  carried,  no^one  can  know  where, 
by  flies,  earthworms,  or  other  living  agencies.  This  is  an 
effective  method  and  can  be  definitely  worked  into  the  habits 
and  sanitary  regime  of  every  home,  and  will  eventually  free 
us  from  all  dangerous  infections ;  whereas  the  most  intelli- 
gent and  conscientious  of  us  cannot  possibly  keep  our  hands 
clean  enough,  boil  or  filter  all  our  drinking  water,  or  con- 
sistently and  always  observe  all  the  precautions  necessary 
to  prevent  infection  if  the  organisms  are  scattered  every- 
where in  soil,  water,  and  food. 

Practical  problems.  The  field  is  so  vast  and  difficult,  and 
knowledge  is  growing  so  fast,  that  the  only  course  for  the 
student  to  follow  is  to  make  connection  with  the  best  sources 
of  information, —  local  boards  of  health  and  the  scientific  de- 
partments of  each  state  and  of  Washington, —  so  as  to  keep 
abreast  of  important  discoveries.  In  this  way  all  will  be  able 
to  help  themselves  and  one  another.  Apply  the  quiz  at  the 
beginning  of  this  chapter  to  all  the  parasitic  diseases  —  of 
plants,  animals,  or  man  —  of  local  importance.  Braun^  has 
described  nearly  400  animal  parasites  of  man  —  31  protozoa, 
40  flatworms,  43  threadworms,  39  ticks,  and  over  250  msects. 
The  niere  figures  indicate  how  little  we  know  about  what  is 
literally  "  eating  "  us  most  of  the  time.  Our  present  knowl- 
edge marks  little  more  than  a  beginning,  and  in  addition  to 
human  parasites  other  hundreds  prey  upon  plants,  and  prob- 
ably thousands  upon  other  animals,  domesticated  and  wild. 
We  shall  be  able  to  suggest  but  a  few  types,  and  all  the  rest 
may  be  studied  along  lines  similar  to  those  indicated. 

Parasitic  protozoa.  Although  discovery  of  protozoan  para- 
sites in  the  blood  of  animals  began  with  the  studies  of 
Chaussat  (1850)  and  Lankester  (1871),  and  several  others 
in  the  interim,  it  was  the  work  of  Laveran  (1880)  on  the 
1  Braun,  The  Animal  Parasites  of  Man.  1908. 


256  CIVIC  BIOLOGY 

parasite  of  malaria  that  aroused  the  scientific  world  to  Ihe 
possible  importance  of  this  subject.  This  was  about  the  time 
Koch  demonstrated  the  tubercle  bacillus  as  the  cause  of  con- 
sumption ;  but  while  bacteriology  has  made  enormous  prog- 
ress, owing  to  definiteness  of  form  and  ease  of  culture  of 
most  bacteria,  the  growth  of  protozoology  lias  been  compara- 
tively slow  because  it  has  been  so  difficult  to  distinguish 
animal  cells  in  and  among  animal  cells,  and  so  hard,  or  im- 
possible, to  discover  methods  of  cultivating  the  protozoan 
parasites  in  artificial  media.  Probably  most  infectious  dis- 
eases the  parasites  of  which  are  still  unknown  —  smallpox, 
yellow  fever,  measles,  scarlet  fever,  spotted  fever,  typhus 
fever,  infantile  paralysis,  foot-and-mouth  disease  —  are  caused 
by  protozoa. 

Amoeba  of  dysentery  —  Entameba  histolytica.  This  parasite  is  said  to 
have  killed  more  northern  soldiers  during  the  late  war  than  bullets. 
It  is  most  active  in  the  tropics,  but  is  not  rare  in  temperate  zones.  It  is 
carried  in  drinking  water  and  on  vegetables  that  are  eaten  raw. 

Rabies,  or  hydrophobia.  The  evidence,  while  not  entirely  conclusive, 
l)oints  to  a  j^rotozoan  present  in  the  saliva  of  rabid  animals  as  the  cause 
of  this  disease.  All  mammals  are  susceptible  to  the  virus,  which  attacks 
the  nervous  system,  following  up  the  nerves  from  a  bite  or  scratch  of 
a  rabid  animal  until  it  finally  reaches  the  brain.  The  animals  trans- 
mitting the  infection,  in  order  of  decreasing  severity,  are  the  wolf,  cat, 
dog,  skunk,  and  other  domestic  animals.  In  case  of  a  suspicious  bite 
the  brain  or  head  of  the  animal  should  be  immediately  sent  to  a  phy- 
sician or  to  the  nearest  laboratory,  where  the  organisms,  known  as 
negri  bodies,  can  be  quickly  demonstrated,  if  present.  As  it  requires 
from  fourteen  to  sixty  days  for  rabies  to  develop  in  man,  there  is  time 
for  the  patient  to  reach  a  Pasteur  institute  for  treatment,  if  the  exami- 
nation indicates  that  the  germs  are  present.  Spread  of  the  disease  is 
prevented  by  muzzling  and  confining  dogs  when  there  is  danger  of  an 
epidemic,  and  it  should  be  more  generally  understood  that  control  of 
cats  may  be  equally  important. 

Parasites  of  malarial  fevers  —  Plasmodium  vivax,  P.  malaria,  P.  immacula- 
tum  or  falciparum.  The  malarial  sporozoa  are  a  gTOup  of  parasites  that 
have  thrown  a  girdle  around  the  earth  wider  than  that  of  the  hookworms, 


CONTROL  OF  ANIMAL  PARASITES  257 

—  from  40°  north  latitude  to  40°  south, —  v(m(iering  many  of  tlie  most 
fertile  valleys  uninhabitable.  Manson  declares  that  malarial  parasites 
cause  more  death,  and  more  predisposition  to  death  from  other  causes, 
than  all  other  human  parasites  taken  together.  Howard  estimated 
(in  1909)  that  they  caused  3,000,000  cases  of  malaria  and  nearly 
12,000  deaths  annually  in  the  United  States,  and  actually  imposed  a 
yearly  tax  upon  this  country  of  not  less  than  $100,000,000. 

The  malarial  parasite  is  carried  to  man  by  the  bite  of  an  anopheline 
mosquito.  The  minute  vermicules,  or  sporozoites,  enter  the  red  corpuscles 
and  grow  until  the  substance  of  the  corpuscles  is  absorbed,  when  they 
divide  asexually  into,  generally,  from  16  to  24  spores,  merozoites.  These 
burst  out  of  the  corpuscles,  and  this,  probably  on  account  of  their 
poisonous  waste  products  set  free  in  the  blood,  causes  the  "chill." 
While  thus  unprotected  in  the  blood  plasma  the  parasites  of  our  com- 
mon, temperate-zone  malarias  (P.  vivax  and  P.  malarice)  may  be  killed 
by  heavy  doses  of  quinine.  The  parasites  of  the  malignant  malarias  of 
the  tropics  are  not  afEected  by  this  drug.  Our  common  malaria  is  caused 
by  P.  vivax,  which  passes  through  its  life  cycle  in  the  blood  every  forty- 
eight  hours  —  the  usual  time  between  chills.  This  is  also  known  as 
tertian  malaria.  Quartan  malaria,  the  other  temperate-zone  type  of 
the  disease,  caused  by  P.  malarice,  which  requires  seventy-two  hours 
to  complete  its  life  cycle,  is  characterized  by  chills  every  third  day. 
Some  authorities  distinguish  two  types  of  malignant  tropical  malaria, 
the  quotidian,  in  which  the  parasite  completes  its  asexual  life  cycle 
in  twenty-four  hours,  and  the  tropical  tertian,  in  which  the  cycle  is 
forty-eight  hours.  All  these  parasites  multiply  sexually  within  the 
anopheline  mosquitoes. 

Reasoning  from  the  above  data,  we  see  that  there  are  three  ways  by 
which  malaria  may  be  banished  from  a  locality :  1.  Exterminate  the 
mosquitoes  (see  Chapter  XI).  2.  Prevent  the  mosquitoes  from  biting 
healthy  people.  3.  Prevent  mosquitoes  from  becoming  infected  by 
biting  malarial  patients.  As  soon  as  every  responsible  member  of 
any  community  becomes  able  to  grasp  these  simple  facts,  that  com- 
munity may  free  itself  completely  from  the  most  vicious  blood  parasites 
that  afflict  mankind. 

The  Piroplasmas ;  Texas  fever,  or  bovine  malaria.  While  the  cattle 
tick  acts  as  carrier,  the  parasite  of  Texas  fever  is  Piroplasma  (Latin 
pirus,  "  a  pear  ")  higeminum,  which  attacks  the  red  blood  cells  of  cattle. 
Tick  extermination  is  banishing  this  costly  j)arasite  from  our  South- 
ern states  (see  Chapter  XV).     Horses,  sheep,  dogs,  and  other  animals 


q\ 


258  CIVIC  BIOLOGY 

have  malaria-like  diseases  caused  by  different  species  of  the  genus 
Piroplasma  —  P.  equi,  P.  ovis,  P.  canis,  etc. ;  and  birds,  frogs,  tui:tles, 
and  many  other  animals  serve  as  hosts  for  blood  parasites  of  other 
kinds. 

Yellow  fever.  No  one  has  been  able  to  demonstrate  the  parasite  of 
yellow  fever,  although  many  investigators  have  hunted  for  it  diligently. 
It  is  so  small  that  it  passes  through  the  pores  of  a  Berkefeld  filter  and 
is  therefore  supposed  to  be  too  small  to  see  with  a  microscope.  This  may 
be  true,  or  the  organism  may  be  soft  and  elastic  enough  to  squeeze 
through  the  pores  of  a  filter,  and  so  transparent  and  unstainable  that 
no  one  could  recognize  it  in  the  field  of  the  microscoj^e.  It  is  generally 
agreed  that  the  organism  is  a  2:)rotozoan,  because  it  is  proved  to  have 
a  life  cycle  in  a  certain  species  of  mosquito  (Aedes  calopus,  formerly 
named  Stegomyia  fasciata)  and  is  transmitted  solely  by  its  bite.  It 
has  been  transmitted  experimentally  by  injecting  into  nonimmunes 
a  few  drops  of  blood  (or  the  serum  of  such  blood  after  passing 
through  a  Berkefeld  filter)  drawn  from  yellow-fever  patients  during 
the  first  three  days  of  the  attack.  After  filling  with  yellow-fever 
blood  the  mosquito  is  not  infective  for  at  least  twelve  days,  indicating 
a  definite  life  cycle,  and  then  the  mosquito  remains  infective  as  long 
as  she  lives  —  fifty-seven  days  in  one  case.  (For  discussion  of  this 
topic  in  relation  to  mosquito  extermination  see  Chapter  XI.^)  Few 
stories  of  discovery  are  more  instructive  or  fuller  of  inspiration  and 
hope  for  the  future  than  this  work  upon  the  cause  and  prevention  of 
yellow  fever.  AVill  some  member  of  the  class  volunteer  to  look  it  up 
and  report? 

Smallpox.  This  is  clearly  a  parasitic  disease,  the  germ  of  which  has 
eluded  discovery,  as  have  the  organisms  that  cause  measles  and  scarlet 
fever  —  epidemic  disorders  of  the  same  class.  We  have,  however,  gained 
control  of  it  by  vaccination.  About  1770  Edward  Jenner  happened  to 
hear  a  woman  say  :  "  I  can't  take  smallpox,  because  I  have  had  cowpox." 
The  idea  was  common  at  the  time  in  several  countries.  Jenner  studied 
the  problem  of  immunity  among  the  dairymaids  for  twenty-six  years. 
On  May  14,  1796,  he  made  his  first  experimental  vaccination,  upon 
James  Phipps,  son  of  one  of  his  friends.  On  July  1  he  vaccinated  James 
again  with  virus  from  a  case  of  smallpox,  at  the  same  time  vaccinating  a 

1  Sternberg,  "The  Transmission  of  Yellow  Fever  by  Mosquitoes,"  Popu- 
lar Science  Monthly,  Vol.  LIX  (1901),  p.  225  ;  Kelly,  Walter  Reed  and  Yellow 
Fever,  New  York,  1907  ;  McCaw,  Walter  Eeed  Report,  Smithsonian  Insti- 
tution, 1905,  p.  549. 


CONTROL  OF  ANIMAL  PARASITES  259 

nonimmune  man  with  the  same  virus.  The  man  took  smallpox  as  usual; 
James  did  not.  Crude  methods  at  first,  making  inevitable  mixed  inocu- 
lations with  other  germs,  raised  violent  objection  to  vaccination,  but 
at  that  time  the  disease  itself  was  so  much  more  serious  than  any  such 
complications,  that  the  practice  spread  rapidly  over  the  world.  Modern 
bacteriological  methods  have  made  the  virus  safe,  so  that  countries 
like  Germany,  in  which  vaccination  under  two  years,  with  revaccination 
between  ten  and  twelve,  is  compulsory,  have  reduced  smallpox  to  the 
vanishing  point.  In  England,  however,  the  old  opposition  has  persisted, 
and  this  has  resulted  in  many  serious  local  epidemics.  The  same  is 
true  of  our  own  country  and  Canada.  A  new  difficulty  has  also  arisen. 
The  disease  has  been  so  nearly  exterminated  that  even  the  most  con- 
scientious people  are  saying :  "  Why  vaccinate  our  children  against  a 
disease  to  which  they  will  never  be  exposed?"  This  argument  is  suf- 
ficiently answered  by  the  many  local  epidemics  of  recent  years.  Study 
carefully  the  history  of  at  least  one  such  epidemic.^ 

No  less  than  eighteen  other  cities  and  towns  in  New  York  State,  and 
several  more  in  other  states,  were  infected  with  smallpox  from  Niagara 
Falls  in  1914,  and  Canada  was  obliged  to  quarantine  against  the  city. 
Is  it  right  for  one  person,  or  one  city,  to  endanger  the  safety  of  others 
in  this  way?  Look  up  the  prevalence  and  mortality  of  smallpox,  and 
methods  of  "inoculating"  from  mild  cases,  before  1800,  and  compare 
with  present  conditions.  Study  also  the  story  of  the  introduction  of 
smallpox  into  America  by  the  Spaniards.  It  is  said  to  have  killed 
3,500,000  natives  in  Mexico. 

The  trypanosomes  {trypanon,  "auger";  somay  "body").  This  genus 
contains  about  sixty  known  species,  which  live  as  free-swimming  para- 
sites in  the  blood  plasma  of  many  vertebrates,  from  fishes  to  man.  Their 
primary  hosts  are  probably  bloodsucking  flies,  which,  at  any  rate,  act  as 
carriers.  Surra,  a  disease  of  cattle,  horses,  and  camels  in  India  and  the 
Philippines,  is  caused  by  T.  evans'd'^  and  nagana,  or  tsetse-fly  disease, 
which  long  made  impossible  the  introduction  of  European  cattle,  horses, 
and  sheep  into  East  Africa,  is  caused  by  a  similar  blood  parasite, 
T.  brucei  Nearer  home  a  serious  disease  of  horses,  dourine,  long  known 
in  Europe,  and  more  recently  reported  from  western  Canada,  is  caused 
by  T.  equiperdum.  This  forms  a  notable  exception  among  diseases  of 
this  class  in  being  spread  exclusively  by  breeding,  and  has  no  known 
connection  with  biting  insects. 

1  Dr.  L.  R.  Williams,  "  Smallpox  Epidemic  at  Niagara  Falls,"  American 
Journal  of  Public  Health,  Vol.  V  (1915),  p.  423. 


260 


CIVIC  BIOLOGY 


Undulating 
sT   "/'Membrane 


Flagellum 


Trypanosoma  gambieme,  which  has  long  been  the  scourge  of  the  west 
coast  of  Africa  and  is  now  spreading  rapidly  up  the  Congo,  is  the  para- 
site of  sleeping  sickness  in  man.  It  is  found  in  the  blood  of  a  number 
of  native  animals  and  is  carried  to  man  by  the  bite  of  one  of  the  tsetse 
flies,  Glossina  palpalis. 

The  flatworms,  flukes,  and  tapeworms  —  Platyhelminthes 
(platysj  **  flat  ** ;  helminthes,  **  worms  ").  The  flatworms 
comprise  a  group  of  diverse  forms  which  vary  in  size  from 

almost  microscopic 
Nucleus  flukes  to  tapeworms 

60  feet  in  length. 
Two  large  classes, 
the  trematodes  (to 
which  the  flukes 
belong)  and  the 
cestodes  (to  which 
the  tapeworms  be- 
long) contain  only 
forms  that  are  par- 
asitic on  or  in  other 
animals.  Two  hosts 
are  commonly  re- 
quired for  one  of 
these  parasites  to 
complete  its  life  cycle,  which  depends  on  the  practice,  com- 
mon among  animals,  of  eating  one  another  raw.  So,  in  parts 
of  the  world  where  fish,  pork,  beef,  and  other  meats  are  com- 
monly eaten  raw,  man  comes  in  for  his  full  share  of  these 
parasites.  People  with  raw-flesh-eating  habits,  coming  to  us 
from  the  ends  of  the  earth,  bring  their  internal  pets  with 
them^  and  proceed  to  take  up  a  collection  of  American 
forms.     The  eggs  are  minute,  and   flies   swallow  them  and 


Fig.  112.    Trypanosoma  gambiense,  from  a  case  of 
sleeping  sickness,  different  forms 

After  Manson 


^  A  tapeworm  has  been  known  to  live  in  man  for  thiity-five  years.  — 
Braun 


CONTROL  OF  ANIMAL  PARASITES 


261 


Man 


pass  them  uninjured  or  may  carry  them  to  human  foods 
as  dust  on  their  feet  —  eggs  of  eighteen  worm  parasites 
have  been  found  on  or  in  flies.  It  is  estimated  that  a  tape- 
worm produces  12,000,000  eggs  a  year,  and  the  flukes  may 
be  equally  prolific.  Such  powers  of  reproduction  demand  a 
number  of  different  hosts,  or  host  and  parasite  would  die 
together.  One  authority 
states  the  problem  thus : 

If  a  liver  fluke  were  to  de- 
posit its  million  or  so  of  eggs 
in  the  bile  ducts  of  the  sheep, 
and  these  were  to  develop  in 
situ,  the  host  could  not  with- 
stand the  increased  drain  upon 
its  vital  resources,  and  host 
and  parasites  would  perish  to- 
gether. Hence  it  is  clear  that 
the  infection  of  a  second  host  by 
trematodes  is  highly  necessary. 


Egg 


Bovine 
(cysticercusS 


Fig.  113.    Life  cycle  of  human  tape- 
worm :  infection  from  raw  beef 


So,  while  many  of  the 
bacterial  parasites  "  don't 
know  any  better"  than  to 
kill  their  hosts  outright, 
these  animal  parasites,  as  a  rule,  sap  and  drain  slowly  and 
are  the  cause  of  prolonged  misery  rather  than  of  death. 
Reasonable  cleanliness  in  rearing  of  farm  animals,  proper  in- 
spection of  meats,  and,  above  all,  proper  cooking  of  meats 
on  the  part  of  everyone  will  finally  relieve  us  from  these 
disagreeable  pests.  The  life  history  of  one  or  two  types 
should  be  generally  known,  and  any  of  the  following  that 
may  be  of  local  interest  should  be  worked  out  to  practical 
conclusions  in  nature  and  in  the  books. 

Liverfluke  —  Fasciola  fiepatica.  The  adult  is  most  commonly  found 
in  the  liver  of  the  sheep,  but  may  occur  in  the  horse,  deer,  camel,  ante- 
lope, goat,  pig,  rabbit,  kangaroo,  beaver,  squirrel,  and,  rarely,  in  man. 


262 


CIVIC  BIOLOGY 


The  eggs  pass  out  through  the  bile  ducts  and  hatch  into  minute,  free- 
swimming  embryos  (the  miracidia),  which  bore  into  fresh-water  snails. 
Within  the  snail  the  parasite  develops  into  a  sporocyst,  which  produces 
still  another  form  of  the  worm,  known  as  the  redia.  The  rediae,  in  turn, 
produce  asexually  other  redise  or  still  another  form  (the  cercarici).   The 

cercariae  are  tadpole-shaped, 
and,  passing  out  of  the  snail, 
swim  about  in  the  water 
until  the  tail  drops  off  and 
they  encyst  upon  the  leaves 
of  plants.  Here  they  are 
eaten  by  animals  and  make 
their  way  up  the  bile  ducts, 
and  so  the  life  cycle  is  re- 
peated. The  adults  in  the 
liver  are  hermaphroditic.  A 
large  species  (Distomum  marj- 
num),  probably  imported 
from  Italy,  may  become  a 
serious  obstacle,  especially 
to  sheep-grazing,  in  portions 
of  the  West.  The  main  rem- 
edy is  avoidanoe  of  low  pas- 
tures during  wet  seasons. 

Tapeworms —  cestodes{ces- 
toSf  "a  girdle")-  ^t^  idea  of 
the  general  form  of  a  com- 
mon tapeworm,  adult  and 
bladder  stages  (cysticercus)^ 
is  given  in  Fig.  114,  In  the 
adult  the  head  is  a  small 
knob  provided  with  four  suckers  and  a  circlet  of  booklets.  This  head 
has  no  mouth  or  sense  organs,  but  serves  merely  to  anchor  the  worm 
to  the  wall  of  the  intestine.  The  neck  is  the  short,  unsegmented  por- 
tion close  to  the  head,  and  behind  this  the  characteristic  segments 
begin  to  form.  These  grow  by  absorption  of  the  digested  food  through 
the  skin;  hence  there  is  no  need  of  digestive  organs,  the  entire  con- 
tents developing  practically  into  reproductive-  cells,  eggs,  and  sperm; 
and  finally  the  joints  {proglottides)  break  off  and  pass  out,  containing 
each  its  many  thousands  of  minute  fertilized  eggs.    In  1861  Leuckart 


Fig.  114.   Tapeworms 
After  Leuckart 


CONTKOL  OF  ANIMAL  PAKASITES  263 

fed  the  ripe  proglottides  from  man  to  calves,  and  was  thus  able  to  dis- 
cover how  man  acquires  this  tapeworm  from  eating  measly  beef.  The 
tiny  egg  hatches  in  the  stomach  of  the  cow,  burrows  through  the  wall 
of  the  intestine,  and  in  from  three  to  six  months  has  grown  to  a 
bladder,  or  cyst  (the  cysticercus),  the  size  of  a  small  bean,  and  is  then 
found  in  the  muscles.  After  the  cysticercus  passes  through  the  human 
stomach,  the  head  everts  (pops  out  like  turning  a  glove-finger),  bringing 
the  hooks  and  suckers  to  the 
outside ;    these  anchor  in  the  Man 

intestine  and  begin  a  new  life 
cycle.  While  the  beef  tape- 
worm (Tcenia  saginata)  may 
cause  some  irritation,  and  un- 
doubtedly steals  some  digested 
food,   it    seldom    does    serious 


injury.      This    is    due    to    the     *  ^^ 

simple  fact  that  its  eggs  can-, 

not  hatch  and  pass  into  cysti- 

cerci  in  the  muscles  or  other 

organs  of  man.    The  cysticer-  "^^  .^^ Man 

cus  stage  is  confined  closely  to  ^^^^^^^^^^^C w  s <     celW 

cattle,  and  the  adult  stage  as  jgr^_  v  / 

closely  to  man.  The  eggs  of  sev-  (cy6lctll\ 

eral  of  the  other  species  do,  how-  ^  J 

ever,  develop  cysticerci  in  man,      Y\g.  115.    Life  cycle  of  pig  tapeworm  ; 

which  renders  them  much  more  infection  from  uncooked  pork 

dangerous  and  sometimes  fatal. 

The  pig  tapeworm  —  T&nia  solium.  This  parasite  is  distributed  the 
world  over,  wherever  the  pig  is  raised  and  eaten  raw  or  rare.  It  is  found 
also  in  the  wild  boar,  sheep,  deer,  dog,  cat,  bear,  and  monkey.  The  eggs 
and  newly  hatched  embryos  (oncospheres)  are  microscopic,  the  latter 
only  0.02  millimeter  in  diameter  —  so  small  that  they  are  easily  carried 
to  foods  on  dirty  hands,  eaten  with  polluted  vegetables,  or  even  swal- 
lowed by  flies  and  carried  to  foods  anywhere.  These  eggs,  if  swallowed, 
may  find  their  way  to  any  part  of  the  body  —  muscles,  eyes,  brain,  and 
even  heart,  and  there  become  cysticerci.  These,  too,  are  large  (6-20  milli- 
meters long  by  5-10  millimeters  thick),  so  that  even  one  may  prove  fatal. 
In  expelling  this  tapeworm  great  care  must  be  used  to  avoid  causing  nau- 
sea, for  a  single  ripe  proglottis,  forced  back  into  the  stomach  and  releas- 
ing its  myriad  embryos,  would  leave  little  chance  for  a  patient's  recovery. 


264 


CIVIC  BIOLOGY 


Tapeworms  of  the  dog  —  Tc^nia  echinococcus.  Unfortunately  our  faith- 
ful friend  has  been  found  to  harbor  twelve  different  species  of  tapeworms. 
The  most  dangerous  of  all  is  T.  echinococcus,  which  has  a  different  life 
history  and  mode  of  growth  from  those  just  described  (see  Figs.  116, 117). 
The  adult  worm  is  minute  (from  2..5  to  6  millimeters  long)  and  occurs 
only  in  the  dog,  wolf,  and  jackal,  often  in  enormous  numbers.  The 
cysticercus  stage  is  found  in  twenty-seven  different  mammals,  including 
man.  Instead  of  forming  a  cyst  with  a  single  sco- 
lex,  or  head,  this  worm  forms  a  cyst  that  may 
grow  for  several  years,  to  the  size  of  a  goose  egg 
or  even  a  "  child's  head,"  and  its  wall  forms  num- 
bers of  vesicles  which  may  develop  hundreds  of 
scolices.  Dogs  infested  with  this  tapeworm  should 
be  mercifully  killed  and  cremated,  and  dogs, 
generally,  should  not  be  permitted  to  lick  the 
face  or  hands  or  to^at  out  of  dishes  used  by  man. 
Tapeworms  of  fishes  —  Dibothriocephalus  latus. 
Fishes  harbor  a  number  of  tapeworms,  which, 
chiefly  in  oriental  countries,  naturally  find  their 
way  into  men,  who  consider  raw  fish  a  delicacy. 
The  broad  tapeworm,  D.  Intiis,  is  found  in  the 
muscles  of  various  fresh-water  fishes,  among 
them  the  pike,  salmon,  and  perch. 

Tapeworms  vary  in  size  from  almost  micro- 
scopic to  ribbons  half  an  inch  broad  and  many 
feet  in  length,  but  this  signifies  little.  The  rate 
of  growth  for  T.  scifjinata  and  D.  latus  has  been 
determined  as  7  centimeters  and  8  centimeters 
per  day  respectively.  At  this  rate,  in  thirty-five 
years  a  broad  tapeworm  might  grow  to  be 
:^406.6  feet  in  lensrth. 


Fi<;.  116.    Dog  tape- 
worm   ( T.   echinococ- 
cus), twentj-^ve  times 
natural  size 

After  Braun 


Roundworms  (nematodes)  and  threadworms  (nemathelminthes) 
{nema,  "  thread  " ;  helminthes^  **  worms'*).  These  worms  attack 
plants,  all  sorts  of  animals,  and  man,  and  are  the  real  terrors 
among  vermian  parasites.  One  species,  Heterodera  radicieola, 
has  been  found  infesting  the  roots  of  four  hundred  and  fifty 
different  plants,  the  list  including  all  garden-truck  crops, 
many  field  crops,  and  a  great  variety  of  fruit  trees,  orna- 
mental trees,  shrubs,  and  flowers.    They  infest  greenhouses 


CONTKOL  OF  ANIMAL  PARASITES  265 

eveiywhere,  often  destroying  entire  crops  and  making  it 
necessary  to  sterilize  the  soil  with  live  steam  or  to  remove 
all  the  earth  frequently  and  disinfect  the  benches.  In  the 
South  they  are  often  most  serious  pests  of  outdoor  garden 


¥ui.  117.    Portion  of  cyst  wall  (7',  ec/i inococcus) 
After  Braun 

and  field  crops.  This  wliole  side  of  plant  injury,  however, 
we  must  leave  for  interested  pupils  to  w^ork  up,  with  the  aid 
of  their  experiment  stations.^ 

General  characters.  Familiar  nematodes  are  vinegar  eels, 
hair  snakes,  and  the  large,  round  worms  so  common  in  dogs, 
horses,  and  man.  As  seen  from  these  examples,  they  vary 
from  microscopic  size  to  1  or  2  feet  in  length.  Many  are 
free-living  in  water  (marine  and  fresh)  or  in  damp  ground, 
but  great  numbers  are  parasitic.     The  life  cycle  of  parasitic 

1  Nematodes  bore  into  the  roots  and  cause  worni-swellings,  galls,  and  knots. 
The  plants  most  seriously  attacked  (Schofield)  are  beets,  carrots,  celery, 
cucumber,  eggplant,  lettuce,  muskn\elon,  watermelon,  clover,  cowpeas,  rape, 
soy  beans,  catalpa,  cherry,  elm,  and  peach.  They  are  most  often  distributed 
in  nursery  stock  and  seed  potatoes,  which  should  be  most  carefully  examined 
for  them  before  planting,  especially  strawberry  and  tomato  plants.  —  See 
Bessey,  ''Root-Knot  and  its  Control,"  Bulletin  No.  217.,  Bureau  of  Plant 
Industry,  United  States  Department  of  Agriculture,  1911 ;  Schofield,  Bureau 
of  Plant  Industry,  United  States  Department  of  Agriculture,  Circular  91  : 
and  Cobb,  Yearbook,  United  States  Department  of  Agriculture,  1914, 
pp.  457-490  (19  illustrations). 


266 


CIVIC  BIOLOGY 


forms  may  be  direct  (that  is,  worm,  egg,  worm  in  the  same 
host)  or  it  may  require  two  or  even  three  hosts  for  its  com- 
pletion. The  sexes  are  usually  distinct.  Typical  nematode 
parasites  are 

Roundworm — Ascaris  lumbricoides.     This  is  the  most  common  para- 
site of  man;  it  is  reddish-yellow,  resembles  the  earthworm  in  general 

shape,  and  may  attain  a  length  of  from 
12  to  15  inches.  It  lives  in  the  small  in- 
testine, and,  being  unattached,  is  easily 
dislodged.  The  life  cycle  is  direct,  the 
eggs  being  taken  in  with  polluted  water 
or  dirty  foods.  Since  they  have  been 
found  to  pass  through,  flies  uninjured, 
these  insects  are  thought  to  be  one  of 
the  active  means  of  distributing  the 
eggs  to  human  foods. 

Pinworm  —  Oxyuris  vermicularis.  This 
is  a  minute  nematode,  from  4  to  12  mil- 
limeters long,  that  affects  children  the 
world  over.     Its  life  cycle  is  direct. 

Gapeworm  —  Syngamus  trachealis.    The 
habitat  of  this  parasite  is  the  trachea 
or  bronchi  of  birds.   The  male  is  smaller 
than  and  permanently  attached  to  the 
female,  and  the  eggs  are  not  laid,  but 
are  set  free  by  the  disintegration  of  the 
mother  in  the  soil.    Here  they  hatch  in 
about    a   week,  in    warm    weather,  the 
embryos  are  picked  up  by  the  birds,  and  the  direct  life  cycle  is  repeated. 
Trichina  worm  —  Trichinella  spiralis.    The  presence  of  this  parasite  in 
man  causes  the  well-known  disease  trichinosis ;  and  our  constantly  re- 
curring epidemics  prove  that,  with  all  the  publicity  given  to  the  matter, 
we  have  not  reached  a  solution  of  the  problem.  Has  proper  attention  been 
directed  to  extermination  of  rats  from  premises  where  swine  are  raised? 
The  course  of  infection  is  indicated  in  Fig.  119.     The  adult  worm, 
the  size  of  a  very  fine  hair  2-4  millimeters  long,  lives  in  the  wall  of 
the  small  intestine,  where  the  female  gives  birth  to  from  1000  to  1500  ^ 


Fig.  118.    Gapeworms,  female 
with  small  male  attached 


1  The  Cambridge  Natural  History  (Vol.  II,  p.  146)  estimates  12,000. 


CONTKOL  OF  ANIMAL  PARASITES      267 

living  young  about  0.1  uiilliuieter  long.    These  burrow  their  way,  or 
are  carried  by  the  blood,  into  the  muscles,  where  they  f  e^d  actively  and 
grow  rapidly.    They  go  to  all  parts  of  the  body,  but  gather  in  greatest 
numbers  in  the  respiratory  muscles,  intercostals,  and  diaphragm.    The 
females  live  and  produce  young  in  the  intestine  for  from  five  to  seven 
weeks,  and  the  first  young  begin  to  reach  the  muscles  in  nine  days  after 
infection ;    hence  the  disease  is  pro- 
longed, and,  from  the  nature  of  the  Rat 
attack,  is  extremely  painful.     After 
thus  feeding  in  the  muscles  for  an 
undetermined    time    the    full-grown 
larva  encysts  (Fig.  120)  and  may  live 
for  years  (thirty-one  in  man,  accord- 
ing to  Braun)  or  until  the  flesh  is 
eaten    raw    by    some    other    animal, 
when  the  life  cycle  is  repeated.    The 
rat  is  continually  eating  its  fellows, 
and  since  this  is  the  most  common 
host  of  the  parasite,  infection  of  these 
pests  is  continuous.  The  pig  eats  the 
dead  rats,  or  the  cysts  in  filthy  sties 
get  into  its  food,  and  so  it  becomes 
a  common  host.    Cats,  naturally,  are 
often   badly   infested.      Cooking    all 
pork  thoroughly  is  the  safeguard  of  J 
man,  but  we  should  always  remem-                                                   4^ 
ber   the   dish   of    spaghetti   and   the                                               Man 
typhoid  epidemic  (p.  242),  and  real-       ^^^  ^^^    ^ife  cycle  and  host- 
ize  that  the  center  of  a  roast,  a  pork           relations  of  trichina  worm 
chop,  or  a  cake  of  fried  sausage  may 

be  scarcely  warmed  through  when  the  outside  is  browned  to  a  crisp. 
Here  is  a  fine  problem  in  civic  biology.  In  connection  with  rat 
extermination,  why  not  examine  the  diaphragms  of  all  rats  and  mice 
killed,  and  tabulate  and  plot  on  a  map  the  results  obtained?  Then 
examine  diaphragm  and  intercostal  muscles  of  all  hogs  slaughtered  in 
the  district,  and  tabulate  and  map  the  results.  Placing  this  map  over 
the  other,  note  whether  there  is  .more  trichina  in  the  hogs  where  rats 
are  numerous  and  badly  infested.  File  all  these  maps  and  tabulations 
in  the  school  library,  so  that  when  the  rats  and  mice  are  exterminated, 
the  next  year's  class  can  examine  the  pork  and  thus  record  progress. 


268 


CIVIC  BIOLOGY 


The  first  school  able  to  report  complete  freedom  from  this  parasite  should 
write  up  the  story  for  the  benefit  of  other  communities.  This  one  job 
might  be  worth  the  t<^tal  cost  of  the  public  schools  in  some  communities. 

Hookworm  disease,  uncinariasis  — 
Uncinaria  americana.  It  only  remains  to 
add  a  word  as  to  life  history  and  mode 
of  infection.  The  adult  worms  live  in 
the  small  intestine,  where  they  gnaw 
holes  in  the  lining  membranes  and 
suck  blood.  Besides  this  the  patient  is 
likely  to  bleed  badly  from  the  wounds. 
How  long  the  adults  may  live  in  the 
intestine,  if  the  case  is  not  treated  and 
no  new  infection  occurs,  is  stated  by 
Stiles  to  be  certainly  six  and  a  half 
years  and  probably  from  ten  to  twelve 
years.  AVith  this  rich  food  supply, 
eggs  are  produced  in  great  numbers. 
These  hatch  in  about  twenty-four  hours 
and  feed  and  grow  in  the  soil  for  about 
five  days.  The  microscopic  embryos 
may  then  be  swallowed  with  polluted 
foods  or  water  (carried  to  foods  espe- 
cially by  flies),  or,  on  coming  in  contact 
with  the  skin,  most  commonly  of  bare 
feet,  they  bore  in,  causing  "ground 
itch,"  and  make  their  way  to  their 
final  destination  in  the  intestine.  Stiles 
says  that  the  embryos  live  in  the  soil 
"  ]>robably  eight  to  twelve  months." 

This  is  a  sectional  problem,  and 
every  school  (especially  every  high 
school)  in  the  South  should  have  in  its 
school  library  the  latest  information  olv 
tainable  from  the  Rockefeller  Sanitary  Commission  for  the  Eradication 
of  Hookworm  Disease,^  and  also  the  bulletins  of  the  United  States  Bureau 
of  Public  Education,  notably  Bulletin,  No.  20,  "  The  Rural  School  and 
Hookworm  Disease,"  Washington,  D.C.,  1914.  Knowledge  is  growing 
so  fast  that  the  latest  and  best  should  be  secured  from  year  to  year. 


Fig.  120.  Trichina  worm  embryo 

cysts  in  luiman  muscle  and  adult 

female  from  iutestinal  wall 

After  Leuckart 


^  Address,  Washiufjton,  D.C. 


CONTROL  OF  ANIMAL  PARASITES      269 

While  the  study  of  these  parasites  of  disease  may  seem 
disagreeable  at  first,  where  can  we  find  keener  inspiration 
than  in  the  thought  of  their  control  by  human  cooperation 


Fk..  I2l,    C;1h.>.s  with  state  inspector  ;  iiic<ii.>  iii  cold  storage 

and  intelligence  ?  By  this  road  only  can  mankind  free  itself 
from  these  time-old  and  world-wide  tormentors  and  sappers 
of  human  life.  So  may  even  the  parasites  of  the  Pharaohs 
help  to  teach  us  lessons  in  cooperative  good  will. 


270 


CHAPTER  XXV 

CIVIC  PROBLEMS  RELATING  TO  MOLLUSKS 

It  is  doubtful  whether  there  is  any  farming  land  in  the  United  States 
which  yields  as  great  a  profit  to  the  acre  as  the  bottoms  which  are  used  for 
oyster-planting  in  Rhode  Island. —  W.  K.  Brooks,  ''The  Oyster,"  p.  135 

The  sea  mussel  {Mytilus  edulis)  is  one  of  the  most  important  food  re- 
sources of  the  ocean,  and  as  yet  France,  Belgium,  and  Holland  are  the  only 
nations  that  appreciate  its  real  food  value,  No  shellfish  grows  so  rapidly 
and  abundantly.  Natural  beds  often  contain  as  many  as  8000  bushels  to  the 
acre,  and  planted  beds  yield  at  the  end  of  three  years  from  4000  to  6000 
bushels  per  acre.  At  present  prices  this  means  from  |1600  to  |2400  per  acre 
every  three  years. 

The  high  nutritive  value  and  low  cost  of  sea  mussels  make  them  the  most 
economical  shellfish  on  the  market.  The  same  money  will  buy  four  times  as 
much  food  in  mussels  as  if  spent  for  long  clams,  and  ten  and  twenty  times 
as  much  as  if  invested  in  oysters  and  lobsters  respectively.  They  are  also 
most  palatable  and  easily  digested.  As  these  facts  come  to  be  better  under- 
stood it  is  hoped  that  the  American  people  will  no  longer  neglect  this 
vast  source  of  food  supply,  but  convert  it  into  the  wealth  of  the  nation. — 
Irving  A.  Field 

Possibilities  of  marine  food  supply.  ''  Four  feet  square  of 
the  ocean  is  capable  of  producing  food  enough  to  support  a 
human  being."  ^  This  statement,  made  in  a  public  lecture 
by  an  eminent  authority,  may  seem  incredible,  but  it  may 
also  serve  to  indicate  that  we  have  scarcely  begun  to  realize 
the  wealth  of  life  in  the  waters.  Of  the  518,900  species 
of  animals  known,  61,000  are  mollusks,  almost  all  aquatic. 
In  regard  to  how  many  of  these  do  we  know  anything? 
Oriental  peoples  utilize  a  considerable  number  of  them,  and 
Europeans,  since  remote  antiquity,  have  feasted  upon  deli- 
cious mollusks,  common  but  unknown  to  us. 

1  Statement  by  Major  McGee  in  an  address  at  the  University  of  Wis- 
consin, 1892. 

271 


272 


CIVIC  BIOLOGY 


Sea  mussels.  These  most  abundant  mollusks  of  our  coasts 
might  supply  the  soup  and  fish  courses  for  every  dimier  in 
North  America  without  strain  upon  their  reproductive  pos- 
sibiKties.  How  many  have  ever  heard  of  them  ?  How  many 
have  tasted  them  in  prime  condition,  or  even  at  all  ?  Some 
may  have  heard  from  irresponsible  sources  that  sea  mussels 
are  poisonous.  So  are  oysters  or  clams  that  are  taken  from 
sewage-polluted  waters  or  that  are  dead  and  half  decayed;  and 

stale  lobsters,  crabs, 
chicken,  veal,  and  even 
milk  may  be  poisonous. 
''  Mussels  taken  from 
pure  water  which  has 
free  circulation  have 
never  been  known  to 
produce  injurious  ef- 
fects. A  New  York 
dealer  who  has  been 
selling  mussels  for 
years  has  never  known 
of  a  case  of  poisoning 
from  them.  Neveithe- 
less,  too  much  emphasis  cannot  be  laid  on  the  fact  that  care 
nmst  be  exercised  in  choosing  proper  localities  for  the  culti- 
vation and  collection  of  mussels  for  market.  They  must  be 
sold  to  the  consumer  m  a  perfectly  fresh  condition  or  serious 
results  will  be  likely  to  follow.'*  ^ 

It  would  be  an  interesting  problem  for  any  community 
unit  to  figure  out  its  aquatic  resources  and  possibilities,  ana- 
lyze the  different  elements,  and  estimate  the  percentage  of 
present  utilization.  For  the  United  States  as  a  whole  this 
is  roughly  attempted  in  the  following  table. 

1  Irving  A.  Field,  "Food  Value  of  Sea  Mussels,"  Bulletin  No.  743  of  the 
United  States  Bureau  of  Fisheries,  1911,  p.  125. 


Fig.  123.    Cleaning  sea  nnissels  commercially 
Photograph  by  I.  A.  Field 


CIVIC  PKOBLEMS  DELATING  TO  MOLLUSKS     273 


Amount  AND  Value  OF  Mollusc  AN  Products  in  the  United  States^ 


Clams,  bard 
Clams,  soft 
Clams,  razor 
Clams,  surf 
Sea  mussels 


Fresh-water  mussel 
Abalones,  shells 
Abalones,  meat . 
Cockles,  conchs. 
Oysters,  Atlantic 
(Jysters,  Pacific  . 
Oyster  shells  .  . 
All  other  shells . 
Squids  .... 
Scallops .... 


Present 


Possible 


j  Yield,  pounds 


Valvie        I  Yield,  pounds 


7,805,000,  ^1.317,000 
8,654,000  553,000 


259,000 

265,000 

8,542,000 

81,869,000 
1,005,000 

146,000 

231,146,000 

2.163,100 


25,000 
21,000 
12,000 

(592,000 
16,000 

35,000 

15,020,200 

693.500 


952,000 1  8,400 

2,562,000  j  43,000 

2,432,000         317,000 


Value 


i|35,000^ 
15,000^0  3 


The  most  instructive  factor  in  such  problems  is  hkely  to 
be  the  causes  that  work  to  depress  actual  below  possible 
resources.  Here  we  shall  find  ignorance  of  values,  lack  of 
knowledge  as  to  life  history  of  forms  and  hence  of  practical 
means  for  development,  and,  above  all,  in  any  development 
of  aquatic  resources,  the  old,  uncivic  spirit  of  piracy,  handed 
down  from  the  times  of  natural  oyster  beds,  which  still  holds 
that  anything  whatsoever  under  water  belongs  to  the  one 
who  can  get  it.  ''  Oh  yes,  this  is  a  fine  location  for  oysters, 
and  I  did  go  to  considerable  expense  and  planted  a  lot,  but 

^  Statistics  furnished  by  the  United  States  Bureau  of  Fisheries  for  1908. 
At  present  the  Bureau  cannot  supply  any  estimates  of  possible  yields.  Fill 
out  the  table  and  keep  it  up  to  date  as  figures  become  available.  Make  a 
similar  table  of  actual  and  possible  yields  for  local  waters. 

^  T)r.  Field's  estimate  of  value  of  sea  mussels  produced  in  1915. 

^  Dr.  Field's  estimate  of  possible  value  of  sea  mussels  produced  in  any 
one  vear. 


274  CIVIC  BIOLOGY 

I  never  got  an  oyster.  As  soon  as  they  grew  to  amount  to 
anything  the  oyster  pirates  came  along  and  cleaned  them  up 
in  a  night.    So  I  had  to  give  it  up."  ^ 

Classification.  Our  common  mollusks  may  be  classified  into  three 
main  groups  : 

1.  Lamellibranchs  (lamella-gilled)  :  Clams,  mussels,  oysters,  scallops, 

—  bivalves,  —  all  are  aquatic  (marine  and  fresh-water).  All  the  great 
food  mollusks  belong  in  this  class,  because  their  gills  enable  them  to 
filter  out  and  feed  upon  the  inexhaustible  supply  of  algae  and  other 
organisms  floating  in  the  water. 

2.  Gastropods  (stomach-footed) :  Snails,  conchs,  periwinkles,  aba- 
lones,  —  typically  coiled  univalve  shells,  —  and  many  shell-less  forms 
(garden  slugs)  are  marine,  fresh-water,  and  terrestrial.  Most  gastropods 
are  carnivorous,  but  a  number  are  vegetarian,  like  the  edible  snails, 
the  slugs,  and  the  periwinkles  and  abalones,  which  feed  upon  the  algae 
and  seaweeds  of  the  bottom. 

3.  Cephalopods  (head-footed) :  Squids,  cuttlefishes,  devilfishes,  octo- 
puses, nautilus,  are  all  marine,  the  molluscan  over-  (or  under-)  lords  of 
the  ocean.  The  cephalopods  are  all  carnivorous,  and  many  of  them  are 
used  for  food  by  oriental  peoples.  Our  common  squids,  used  now  for 
fish  bait,  are  good  food  mollusks. 

Typical  problems  and  life  histories.  While  schools  along  the  seacoasts 
have  the  advantage,  the  mollusks  of  our  rivers,  lakes,  and  ponds,  and 
even  of  our  woods  and  gardens,  offer  problems  of  no  mean  interest. 

Oysters.  Osirea  virginica  is  the  native  oyster  of  the  Atlantic  coast 
from  Cape  Cod  to  the  Gulf  of  Mexico.  It  has  the  reputation  of  being 
the  finest  edible  oyster  in  the  world.  A  small,  starveling  variety,  the 
"  coon  oyster,"  forms  extensive  natural  beds  throughout  the  salt-marsh 
sedges  and  mangrove  swamps  of  the  Southern  states.  A  small  but 
delicious  species,  0.  lurida,  is  native  to  the  American  Pacific,  and 
young  0.  virginica,  since  1870,  have  been  shipped  across  the  continent 
to  grow  and  fatten  in  the  favored  coves  of  the  Pacific  coast.  Almost 
the  entire  Pacific  coast  line,  however,  from  Puget  Sound  to  Mexico,  is 
a  waste  of  desert  sand,  unindented  and  open  to  the  ocean  front,  with 
line  after  line  of  huge  beach  combers  out  as  far  as  the  eye  can  reach 

—  terrific  instead  of  "  pacific,"  and  not  at  all  suited  to  the  oyster.  The 
United  States  Bureau  of  Fisheries  has  made  repeated  experiments  in 
colonizing  Atlantic  oysters  in  favored  places  along  the  Pacific,  but, 

1  Experience  of  a  shore  owner  on  the  Chesapeake. 


CIVIC  PKOBLEMS  KELATING  TO  MOLLUSKS     275 

while  they  evidently  find  food  and  conditions  generally  favorable  to 
growth,  there  has  been  difficulty  in  getting  them  to  spawn.  It  is 
claimed  that  they  have  now  become  acclimated  and  are  spawning 
freely  in  some  of  the  inlets  of  the  Washing"ton  coast.  If  this  is  true, 
such  oysters  ought  to  be  used  exclusively  for  seeding  all  available  coves 
of  the  Pacific  coast,  which  are  few  at  best.  To  use  them  otherwise, 
until  this  is  done,  would  be  monumental  folly.  Pacific-coast  schools 
should  give  special  attention  to  this  problem. 

Ofttrea  edidis  is  the  native  oyster  of  the  European  Atlantic,  and,  like 
O.  lurida^  is  hermaphroditic,  while  0.  virginica  is  bisexual.  For  a  com- 
munity interested  in  oyster  culture  a  good  topic  would  be  a  comparison 


Fig.  124.    Ostrea  virginica 

Left,  old  shell  covered  with  young  oystei-s ;  middle,  shells  of  four  large  specimens 
about  6  inches  long ;  right,  sliell  of  an  old  oyster  riddled  by  boring  sponges 

of  local  with  European  methods.  Possibly  France  has  attained  nearest 
to  100  per  cent  efficiency  in  the  use  of  her  available  oyster  beds.  The 
French  attend  not  only  to  the  rearing  of  the  oysters  but  to  the  propa- 
gation of  certain  kinds  of  algae  which  impart  desired  colors  and  flavors 
to  the  finished  product. 

The  civic  problem  which  must  be  solved  by  the  rising  generation  is 
that  of  developing  the  oyster  industry  to  as  near  100  per  cent  efficiency 
as  possible.  Much  as  we  have  already  done  in  this  direction,  probably 
not  more  than  2  per  cent  of  the  possible  j)roduction  of  American  waters 
has  been  attained.  How  we  can  develop  to  100  per  cent  efficiency  in 
each  community  is  the  problem  for  each  community  to  solve. 

Sea  mussels  —  Mytilus  edulis  (and  other  species).  The  range  of  Mytilus 
is  circimipolar,  fringing  the  northern  coasts  from  Japan  around  to  the 


276  CIVIC  BIOLOGY 

Mediterranean  and  from  North  Carolina  around  through  the  Arctic 
Ocean  to  San  Francisco.  In  depth  it  ranges  from  halfway  between  tide 
marks  to  probably  100  fathoms.  Under  most  favorable  conditions,  in 
American  waters,  the  mussels  may  grow  to  an  average  length  of  from 
2  to  3  inches  in  a  year.  In  England,  by  the  bed  system  of  cultivation, 
they  require  two  and  generally  three  years  to  attain  a  length  of  2  inches; 
but  in  France  this  size  is  secured,  by  the  huchot  method,  in  a  year  and 
a  half.  A  female  mussel  has  been  observed  to  lay  12,000,000  eggs  in 
fifteen  minutes,  almost  the  entire  substance  of  the  animal,  except 
the  heart  and  gills,  being  transformed  into  eggs  or  sperm,  which  are 
thus  quickly  shed  once  a  year.  The  spawning  season  varies  with  lati- 
tude and  with  the  temperature  of  local  waters,  extending  from  Feb- 
ruary to  September;  and  since  the  mussels  are  in  prime  condition  when 
full  of  reprodiu^tive  products,  the  beginning  of  the  spawning  season 
should  be  determined  for  each  typical  bed  in  a  locality,  to  the  end  that 
the  yearly  crop  may  be  harvested  at  the  right  time,  that  is.  Just  before 
spawning  occurs.  Thus  mussels  may  ha  made  to  fill  the  gap  in  the 
markets  from  May  to  August,  when  oysters  are  out  of  season ;  and,  in 
fact,  according"  to  the  extended  investigations  of  Dr.  Field,  sea  mussels 
luay  be  found  in  fair  or  prime  condition  every  mouth  in  the  year.  Of 
course,  as  long  as  no  one  knows  how  good  they  are,  this  vast  food 
supply  will  continue  to  go  to  waste.  As  a  matter  of  practical  biology; 
then,  why  not  arrange  for  a  course  of  mussels  in  class  banquets  or 
other  entertainments,  and  agree  to  call  for  them  frequently  in  local 
restaurants  and  hotels.  When  once  mussels  have  been  tried,  the  de- 
mand for  them,  and  consequently  the  supply,  will  grow  until  the  whole 
country  is  benefite<l. 

Soft,  or  long-necked,  clams  — Mya  arenaria.  riiis  is  popular  for  claui- 
bakes  along  the  Xew  England  shore  and  far  inland.  Mija  ranges  from 
South  Carolina  to  the  Arctic  Ocean,  but,  unlike  Mytilus,  has  not  as  yet 
reached  the  Pacific  by  that  route.  It  was,  however,  introduced  into  San 
Francisco  Bay  in  1870,  and  spread  rapidly.  It  appeared  in  Willapa  Bay, 
Washington,  in  1880,  was  transplanted  to  Puget  Sound  a  little  later, 
and  has  become  abundant  at  many  points  in  the  Sound.  Pacific-coast 
schools  may  well  lay  emphasis  on  this  problem ;  for  in  this  burrowing 
clam  we  may  possibly  have  the  form  best  able  to  transform  the  endless 
barren  sand  wastes  of  the  Pacific  into. productive  sea  gardens.  Mya  can 
be  much  more  easily,  cheaply,  and  quickly  raised  than  oysters,  coming 
to  market  size  in  a  year,  under  favorable  conditions ;  and  the  young,  in 
passing  from  the  free-swimming,  larval  stage  to  the  adult  stage,  often 


CIVIC  PROBLEMS  RELATING  TO  MOLLUSKS     277 

gather  in  solid  masses  iu  tide  pools,  a  single  find  of  this  sort  often  suf- 
ficing to  plant  acres  of  barren  beach  at  almost  no  cost.  Antiquated  and 
utterly  destructive  beach  laws  and  customs,  remains  of  piracy,  are  keep- 
ing barren  and  totally  unproductive  thousands  of  acres  of  New  England 
beaches  and  flats  that  might,  under  enlightened  civic  management,  be 
yielding  per  acre  from  |300  to  $500  worth,  or  more,  of  these  delectable 
mollusks.  These  places  are  not  adapted  to  the  culture  of  either  sea 
mussels  or  oysters. 

Hard,  or  little-neck,  clam  (quahog)  —  Venus  mercenaria.  As  relations 
now  stand,  Venus  ranks  second  in  commercial  importance  among  the 
Atlantic-coast  mollusks.  It  is  par  excellence  the  chowder  clam  of  the 
country,  and  when  young  it  is  also  relished  on  the  half  shell.  In  range 
Venus  is  a  soutliern  form,  thus  supplementing  Mt/a.  The  two  overlap  from 
Cape  Cod  to  South  Carolina,  and  from  the  Chesapeake  southward  and 
through  the  Gulf  of  Mexico  Venus  lives  in  enormous  beds,  unknown 
and  consequently  unutilized.  This  clam  has  short  siphons  (whence  the 
name  "  little-neck  "),  and  buries  itself  only  about  the  depth  of  its  shell. 
It  supplements  the  oyster  in  marine  aquiculture,  growing  best  on  soft, 
muddy  bottoms  from  between  tide  lines  out  to  water  ten  fathoms  or 
more  in  depth. ^ 

Scallops  —  Pecten  irradians  and  P.  magellanicus.  Epicures  have  assured 
us  that  'Hhe  scallop  is  the  daintiest  of  all  foods  the  waters  produce."^ 
The  smaller  pecten,  P.  irradians,  occurs  in  the  shallow,  eel-grass  waters 
south  of  Cape  Cod,  down  the  southern  Atlantic,  and  in  the  Gulf  of 
Mexico.  AVhile  piratical  methods  are  exterminating  it  from  its  north- 
ern range,  farther  south  there  are  quantities,  totally  imknown  and 
unutilized,  which  might  support  profitable  fisheries. 

The  northern,  or  '"giant,"  scallop  (P.  magellanicus')  lives  in  water 
from  40  to  60  fathoms  deep,  over  rocky  bottoms  difficult  to  dredge,  which 

1  Kellogg  figures  the  crop  from  an  acre,  one  year  after  planting  with  small 
seed  little-necks,  at  600  bushels,  worth  at  least  ^3  per  bushel,  that  is,  $1800, 
the  net  profit  being  probably  about  $1000.  ''  Present  prices  for  this  baby 
clam  are  high,  the  clammer  sometimes  receiving  four  dollars  a  bushel  for 
his  catch,  while  one  who  orders  them  on  the  half  shell  at  a  Boston  or  New 
York  restaurant  pays  for  them  at  the  rate  of  fifty  dollars  a  bushel." — 
Kellogg,  Shellfish  Industries,  p.  220 

2  Demurrer  filed  in  favor  of  Myiilus,  taken  in  prime  condition  and  fried 
or  roasted  brown  in  cracker  crumbs.  To  make  a  practical  test  and  settle 
this  controversy,  have  both  scallops  and  mussels  prepared  alike  and  served 
ftt  a  biology-class  banquet.  Decide  by  ballot  at  end  of  banquet,  and  print 
result,  with  discussions  that  may  arise,  in  local  papers. 


278 


CIVIC  BIOLOGY 


makes  it  scarce  in  the  markets  except  along  the  Maine  coast.  This 
scallop  reaches  a  diameter  of  7  inches,  and  the  sexes  are  distinct,  while 
the  southern  pecten  is  hermaphroditic  and  seldom  grows  over  half  this 
diameter.  The  life  history  of  P.  irradians  has  been  studied  carefully 
and  has  a  direct  bearing  on  its  practical  utilization.  These  pectens  are 
spawned  in  midsummer,  grow  rapidly,  and  spawn  when  a  year  old.  They 
continue  to  grow,  but  rarely  survive  to  spaw^n  a  second  time,  most  of 
them  dying  in  the  early  spring  of  their  second  year.    It  is  thus  clear 


Fig.  125.    Digging  soft  clams 
United  States  Bureau  of  Fisheries 


gain  to  utilize  all  of  these  pectens  over  one  year  old.  This  will  not 
cause  any  decrease  in  the  species  if  all  those  under  a  year  old  are  left 
on  the  breeding  grounds. 

The  fine  Pacific  clams,  the  geoduck,  or  giant  clam  (Glycimeris  gen- 
erosa),  that  grows  to  weigh  6  pounds,  the  gaper  clam  {Schizothcerus 
nuttalli),  now  becoming  rare  in  the  western  markets,  the  western  little- 
neck  (Tapes  staminea),  and  the  butter  clam  (Saxidomus  nuttalli),  along 
with  the  western  species  of  Mytilus  and  the  closely  similar,  and  equally 
edible.  Modiolus,  are  all  fine  subjects  for  study  in  western-coast  schools. 
The  Pacific  has  also  two  valuable  scallops. 

Life  history.  In  general  outline,  the  life  histories  of  all  the  marine 
bivalves  described  above  are  similar.  Eggs  are  produced  by  the  millions, 
and  hatch  within  a  few  hours  into  free-swimming  embryos  entirely 


CIVIC  PROBLEMS  RELATING  TO  MOLLUSKS     279 


unlike  the  parent.  This  free-swinmiiug  period  enables  the  species  to 
be  distributed  widely  by  tides  and  currents,  and  it  also  offers  opportu- 
nity for  the  culturist  to  increase  his  stock  almost  beyond  belief  by  mak- 
ing conditions  more  favorable  for  the  young.  The  embryo  oyster,  for 
example,  swims  for  from  one  to  six  days.  By  the  end  of  this  time  the 
shell  begins  to  form  and  it  must  sink  to  the  bottom.  If  it  happens  to 
land  on  a  clean,  hard  surface,  it  may  survive ;  if  it  falls  in  an  ooze  of 
slime  or  silt,  it  is  quickly  smothered.  So  the  oyster  culturists  scatter  clean 


Fig.  126.   Pearl  fishing  in  the  Mississippi  River 
Photograph  by  the  author 

shells  —  "cultch  " — over  the  bottom  about  the  beginning  of  the  spawn- 
ing season.  If  too  many  of  the  young  oysters  succeed  in  attaching  to 
these,  they  must  be  dredged  up  and  the  clusters  broken  apart  and  re- 
planted evenly  over  the  bottom,  so  that  all  may  find  food  and  have 
room  to  grow.  The  left  valve  of  the  oyster,  which  is  spoon-shaped, 
always  makes  contact  with  the  support  and  is  quickly  cemented  to  it  by 
a  secretion  like  that  which  forms  the  shell.  The  other  marine  bivalves 
anchor  by  means  of  a  peculiar  mechanism,  the  byssus  (hyssos,  "  fine  textile 
fiber  "),  which  is  secreted  by  a  gland  in  the  foot  as  a  viscous  fluid  that 
hardens  on  contact  with  the  water.  The  byssus  is  retained  in  Myfilus, 
but  is  lost  in  the  clams  and  scallops  soon  after  they  assume  adult  form. 
Fresh-water  mussels  ("  clams  ")  —  Umomd<t.  The  fresh  waters  of  east- 
ern J^orth  America  contain  about  600  species  of  lamellibranchs. 
Tough,  and  muddy  of  taste,  they  were  considered  as  food  only  for 


280 


CIVIC  BIOLOGY 


muskrats  until  discovery  of  their  pearls  and  still  more  valuable  shells 
turned  prosaic  farming  districts  into  "  pearl  fisheries  "  and  developed  a 
flourishing  industry.  As  with  everything  else,  from  forests  to  clams, 
when  it  is  discovered  to  possess  commercial  value,  the  American  public 
lias  hastened  to  kill  the  goose  that  laid  the  golden  eggs ;  so  the  waters, 
many  of  them,  are  already  dei)leted  and  the  shell  industry  is  in  danger. 


Fig.  127.    Mussel  in  sand,  moving  in  direction  of  large  arrow,  foot  pro- 
truding from  anterior,  and  inhalent  and  exhalent  siphons  from  posterior. 

end  of  shell 


As  a  consequence  the  I'nited  states  Bureau  of  Fisheries  has  made  exten- 
sive surveys  to  discover  the  distribution  of  useful  species,  and  has  estab- 
lished a  biological  station  at  Fairport,  Iowa,  to  study  practical  methods 
of  propagating  mussels  in  the  great  Mississippi  basin.  All  this  is  likely 
to  prove  a  futile  expenditure  of  time  and  money,  imless  communities  can 
learn  to  control  their  piratical  impulses  and  members,  and  unite  upon 
rational  plans  for  conservation  of  these  industrial  resources. 

It  is  estimated  that  a  "  niggerhead  "  requires  from  fifteen  to  eighteen 
years  to  grow  to  a  diameter  of  four  and  one-half  inches,  and  pearls  of 
value  are  never  found  in  mussels  less  than  five  years  old.  Other  species 
of  nearly  equal  value  may  be  grown  in  a  shorter  time  —  possibly  in  from 
four  to  six  years.  Growth  lines  on  the  shell  are  commonly  taken  to  indi- 
cate age,  or  at  least  the  years  required  for  a  mussel  to  reach  adult  size. 


CIVIC  PROBLEMS  RELATING  TO  MOLLUSKS     281 

It  is  quite  possible  tliat  these  humble  creatures  are  doing  a  work  of 
value  many  times  greater  than  that  represented  by  their  shells  and 
pearls,  in  the  constant  purification  of  our  lakes  and  streams.  Experi- 
ment has  shown  that  a  good-sized  mussel  filters  about  four  gallons 
of  water  through  its  gills  per  hour,  and  since  it  breathes  and  feeds 
continuously,  this  means  nearly  100  gallons  daily  year  in  and  year  out. 


Fig.  128.    Fresh-water  mussels,  female,  male,  and  side  view,  showing 
growth  lines 

Set  up  two  perfectly  clean  glass  aquaria  exactly  alike,  put  a  ]iius- 
sel  in  one  of  them,  and  note  the  difference  in  clearness  of  the  water. 
What  may  this  mean  in  keeping  reservoirs  and  park  waters  clear  and 
wholesome  ? 

Glochidia  (glochis,  "arrow  point")-  ^</^'  ^ii-^(ory.  The  eggs  develop  in 
the  gills  of  the  i»arent  mussel  into  minute  bivalves  so  unlike  the  adult 
that  they  were  long  considered  parasites.  I'hese  are  the  f/Ioch'dia  ainl 
when  ripe  they  are  extruded  into  the  water.  Here  further  development 
depends  upon  their  attachment  to  gills,  fins,  or  other  parts  of  fishes. 
A  long  byssus  thread  is  present  and  probably  helps  in  catching  the  fish, 
and  some  species  have  the  valves  tipped  with  shari>barbed  hooks,  which 
catch  into  the  skin  of  the  fish  when  they  are  snapped  together.     The 


282 


CIVIC  BIOLOGY 


species  that  do  not  have  hooks  are  taken  in  with  the  breathing  currents 
of  fishes  and  clamp  on  to  the  gill  filaments.  The  tissues  of  the  fish  grow 
over  the  glochidia,  and  within  the  sac  thus  formed  they  grow  and 
change  into  the  adult  form.  Finally,  at  the  end  of  from  two  to  ten 
weeks,  according  to  their  species  and  the  temperature  of  the  water, 

they  kick  themselves  out  of  these 
cysts  and  begin  their  free  life  on 
the  bottom.  So  far  as  we  know,  this 
is  the  only  way  a  young  fresh-water 
mussel  can  be  carried  over  this  criti- 
cal stage  from  glochidium  to  adult, 
and  this  means  that  extermination 
of  fishes  must  result  in  extermina- 
tion of  mussels  as  well. 

Problems.  Ascertain  from  the 
nearest  markets  which  species  of 
mussels  produce  the  most  valuable 
shells,  and  make  a  collection  of  these 
for  the  school  museum. 

Examine  specimens  of  valuable 
species  and  make  a  table  showing 
the  months  when  the  gills  contain 
glochidia.  Discuss  the  advisability 
of  a  closed  season  including  these 
months.  Estimate  the  number  of 
glochidia  per  adult  mussel. 

Examine  all  fishes  caught  for 
glochidia  in  gills  or  fins  and  skin. 
How  many  may  a  fish  carry? 

Try,  possibly   with   the    help   of 

the    state    fish    commission    or    the 

United  States  Bureau  of  Fisheries, 

to  make  a  plan  for  the  best  possible  utilization  of  streams,  ponds,  and 

lakes  in  the  locality,  for  both  mussel  and  fish  culture. 

Gastropods.  Comparatively  slight  civic  values  attach  to  this  group. 
The  abalones  are  of  interest  in  California,  and  the  periwinkle  (Littorina), 
brought  to  the  Atlantic  coast  from  Europe,  where  it  is  used  for  food,  has 
become  abundant  from  New  England  southward.  It  is  also  of  value  in 
cleaning  oyster  beds  of  seaweeds.  A  number  of  other  marine  forms,  the 
oyster  drill  (^Urosalpinx), Fulgur,  and Natica,  feed  upon  oysters  and  clams. 


Fig, 


129.     Garden  slugs  spinnin< 
mucous  threads 

Photograph  by  the  author 


CIVIC  PROBLEMS  RELATING  TO  MOLLUSKS     283 

The  edible  snail  {Helix  pomatia)  is  imported  from  Eurojie  and  is 
raised  in  specially  fenced  gardens  and  fattened  for  market.    This  may 


Fig.  130.    A  common  land  snail 


be  studied  as  an  interesting  novelty  in  most  American  communities. 
For  all  we  know,  may  not  our  big,  fat  garden  slugs  be  food  delicacies  ? 

Compare  garden  slugs  with  marine  or  fresh-water  snails,  which  they 
may  be  seen  to  resemble,  except  in  respect 
to  the  rudimentary  shell.  These  slugs  are 
often  as  destructive  in  gardens  as  any  in- 
sect, and,  being  nocturnal,  are  little  known. 
Collect  the  eggs  (translucent,  yellowish, 
about  the  size  of  buckshot,  in  masses  of 
thirty  or  more,  found  in  damp  places  under 
boards)  and  keep  them  in  a  glass  jar  or 
aquarium  to  watch  their  development.  If 
the  life  history  of  these  pests  were  better 
known,  we  might  control  them  more  effec- 
tively about  our  gardens  and  greenhouses. 

In  connection  with  other  field  work, 
make  a  collection  of  common  marine, 
fresh-water,  and  terrestrial  gastropods. 
Keep  them  in  suitable  aquaria  or  vivaria, 
to  study  habits  and  foods.  Note  that  some 
snails  are  "  left-handed "  and  most  are 
"  right-handed."  (If  held  with  opening  up 
and    spire    pointing    away    from    you,   the 

dextral  shells  have  the  opening  to  the  right,  the  sinistral,  to  the  left.) 
The  commonest  and  most  interesting  are  the  pond  snails,  belonging 
to  the  genus  Physa,  which  can  be  readily  distinguished  by  their  sinistral 


Fig.  131.    Common  snails, 
sinistral  and  dextral 


284 


CIVIC  BIOLOGY 


shells.  If  kept  in  a  balanced  aquarium,  Physa  will  serve  to  demonstrate 
most  of  the  interesting  reactions  —  locomotion,  spinning  mucous  threads, 
feeding,  breathing,  egg-laying  —  of  this  group  of  moUusks.  The  eggs 
will  be  laid  in  transparent  masses  of  jelly  on  the  glass,  and  will  thus 
afford    opportunity  to    obsei-ve    the    embryological    development  of    a 

gastropod. 

Tyrian  purple,  the  dye,  was  obtained 
from  marine  gastropods,  which  have 
been  known  as  purpuras  since  remote 
antiquity. 

Cephalopods.  No  more  interesting- 
specimens  for  the  marine  aquarium  can 
be  had  than  the  young  of  our  common 
squids,  with  tlieir  flashing  changes  of 
color,  their  hiding,  ink-cloud  maneuvers 
(equaled  only  by  the  most  astute  politi- 
cians), and  their  lightning-like  efficiency  in  catching  fish  nearly  as 
large  as  themselves.  It  is  almost  impossible  to  believe  that  these  keen, 
active,  intelligent  creatures  are  really  mollusks. 

The  cephalopods  furnish  bait  for  our  cod  fisheries,  sepia  for  artists, 
and  cuttle  bone  for  canaries,  and  are  used  extensively  for  food  along  the 
Mediterranean  and  among  oriental  peoples.  Some  of  the  deep-sea  forms 
reach  enormous  size ;  we  hear  thrilling  stories  of  their  encounters  with 
whales,  and  they  probably  furnish  whatever  basis  there  may  be  for 
sailors'  yarns  of  sea  serpents. 


Fig.  132.    Atlantic  squid 


CHAPTER  XXVI 
CRUSTACEA 

The  tislies  in  a  school  of  mackerel  are  as  numerous  as  the  birds  in  a  flight 
of  wild  pigeons.  Goode,  in  his  "  History  of  Aquatic  Animals,"  tells  of  one 
school  of  mackerel  which  was  estimated  to  contain  a  million  barrels,  and 
of  another  which  was  a  windrow  of  fish  half  a  mile  wide  and  at  least  twenty 
miles  long ;  but  while  the  pigeons  are  plant  eaters,  the  mackerel  are  rapa- 
cious hunters,  pursuing  and  devouring  the  herrings,  as  well  as  pteropods  and 
pelagic  Crustacea. 

Herring  swarm  like  locusts,  and  a  bank  of  herring  is  almost  a  solid  wall. 
In  1879  three  hundred  thousand  river  herring  were  landed  in  a  single  haul 
of  the  seine  in  xVlbemarle  Sound  ;  but  the  herring  are  also  carnivorous,  each 
one  consuming  myriads  of  copepods  every  day.  In  spite  of  this  destruction 
and  the  ravages  of  armies  of  medusse  and  siphonophores  and  pteropods,  the 
fertility  of  the  copepods  is  so  great  that  they  are  abundant  in  all  parts  of 
the  ocean,  and  they  are  met  with  in  numbers  which  exceed  our  powers  of 
comprehension. 

On  one  occasion  the  Challenger  steamed  for  two  days  through  a  dense 
cloud  formed  of  a  single  species,  and  they  are  found  in  all  latitudes  from 
the  Arctic  regions  to  the  equator,  in  ma&ses  which  discolor  the  water  for 
miles.  We  know,  too,  that  they  are  not  restricted  to  the  surface,  and  that 
banks  of  copepods  are  sometimes  a  mile  thick.  When  we  reflect  that  thou- 
sands would  find  ample  room  and  food  in  a  pint  of  water,  we  can  form  some 
faint  conception  of  their  universal  abundance. 

Modern  microscopic  research  has  shown  that  these  simple  plants  [the  algie 
in  the  water],  and  the  globigerinae  and  radiolarians  which  feed  upon  them, 
are  so  abundant  and  prolific  that  they  meet  all  the  demands  made  upon 
them  and  supply  the  food  of  all  the  animals  of  the  ocean. 

This  is  the  fundamental  conception  of  marine  biology.  The  basis  of  all 
the  life  in  the  modern  ocean  is  to  be  sought  in  the  microorganisms  of  the 
surface.  — W.  K.  Brooks,  "Salpa,"  pp.  146-147 

All  the  ingenious  men,  and  all  the  scientific  men,  and  all  the  fanciful 
men,  in  the  world,  with  all  the  old  German  bogy  painters  into  the  bargain, 
could  never  invent  .  .  .  anything  so  curious,  and  so  ridiculous,  as  a  lobster. 
—  KiNosLEY,  "  Water  Babies  " 

285 


286 


CIVIC  BIOLOGY 


SPECIES 

TIME ^ 


UNDER 
NATURAL 
CONDITIONS 


Attack 
by  Man 


Adults. 
Lobsterlings 

-i-^ 


UNDER 
HUMAN 

CONTROL 


4=5= 


[Natur  ab  Enemies  ],-\i..  ^  ^^ 


Fig.  133.  Diagram  expressing  Brooks's  law  of  the  extermination  of  a  species 
by  man  as  applied  to  the  lobster  problem 

The  species  is  shown  flowing  along  from  an  indefinite  past  nnder  natural  condi- 
tions, with  minor  fluctuations,  hut  maintaining  a  practically  constant  population, 
having  adjusted  itself  to  its  natural  enemies  hy  developing  great  fecundity,  as 
seen  in  the  wide  stream  of  eggs  and  larvae,  most  of  which  are  taken  in  the  larval 
stage  hy  natural  enemies.  At  the  large  arrow  civilized  man  attacks  the  slender 
stream  of  adult  lohsters  which  nature  has  selected  to  keep  up  the  supply  of  eggs. 
This  strikes  the  species  as  a  "catastrophe."  Man's  attack  is  unlike  that  of  all 
other  enemies.  Instincts  of  self-pi'eservation,  thickness  of  shell,  and  large  size, 
which  made  the  adult  lobsters  almost  immune  from  attacks  hy  other  enemies, 
all  ai-e  of  no  avail.  Although  man  takes  hut  a  small  numher  of  adults,  the  bal- 
ance is  disturbed,  fewer  eggs  are  produced,  natural  enemies  crowd  and  tend  to 
take  a  larger  proportion,  and  the  species  swiftly  approaches  extermination.  Even 
if  man  ceases  his  attack  when  the  numbers  have  become  reduced  so  as  to  render 
their  further  pursuit  unprofitable,  natural  enemies  may  kill  off  the  stragglers,  and 
before  we  realize  what  has  happened,  the  race  is  extinct.  If  we  did  .shut  off  all 
the  streams  of  young  and  adults  at  the  point  of  the  large  arrow,  we  should  have 
a  picture  of  the  extermination  of  the  lobster.  Under  human  control,  if  even  a 
few  adult  breeders  are  left,  man  can  increase  the  number  to  any  desired  amount ; 
he  can  lift  the  eggs  and  young  above  the  reach  of  natural  enemies,  or  crowd 
them  down,  or  both,  and  .so  increase  the  .species  to  the  limits  of  room  or  of  food 
supply.  This  is  what  we  hope  is  now  being  done,  and  we  shall  watch  the  future 
curves  of  increase  in  the  expectation  that  the  price  of  lobsters  may  begin  to 
decline  toward  reasonable  limits.  This  diagram  is  applicable  to  any  species  ex- 
terminated or  in  danger  of  extermination  by  man  —  passenger  pigeon,  dodo,  great 
auk,  and  many  other  species  now  lost  to  the  world 
286 


CRUSTACEA 


287 


General.  Crustacean  problems  parallel  those  of  the  mol- 
lusca.  Lobsters,  crabs,  shrimps,  and  crawfish  are  valuable  for 
food.  Some  of  the  most  higlily  prized  species  require  to  be  pro- 
tected by  law,  and  we  are  beginning  to  work  out  methods  for 
their  artificial  propagation.  Some  of  the  terrestrial  crawfish 
are  locally  injurious  to  vegetation.  There  is  this  difference: 
crabs  and  lobsters  move  about  more  freely  than  clams  and 
oysters,  and  hence  are  not  so  well  suited  to  stable  aquicul- 
ture.  On  this  account  the  United  States  Bureau  of  Fisheries, 
and  the  fish  commissions  of  the  states  concerned,  must  assume 
responsibility  for  keeping  up  the  supply  by  propagation,  since 
this  cannot  be  done  with  profit  by  private  individuals. 

Economic  value.  The  table  below  presents  the  chief  eco- 
nomic Crustacea,  and  its  most  suggestive  feature  is  likely  to 
be  the  wide  difference  between  actual  and  possible  utilization 
of  these  resources. 


Crustacean 

Products 

OF 

THE 

United  States  in  1908 

Actual  Value 

Possible  Value  » 

Lobsters                ... 

11,931,000 

912,000 

494,000 

127,000 

32,000 

Blue  crabs 

Shrimps  prawns 

Pacific  crabs 

Crawfish 

Classification.  The  Crustacea  are  divided  into  two  main 
groups,  the  Entomostraca  (mostly  microscopic  or  small,  includ- 
ing the  ostracods,  copepods,  and  barnacles)  and  the  Malacos- 
traca  (the  lobsters,  crawfish,  shrimps,  prawns,  and  crabs). 

Entomostraca.  Although  inconspicuous  and  little  known, 
these  minute  Crustacea  are  of  the  greatest  biological  signifi- 
cance. If  we  had  them  all  gathered  into  a  ball,  and  all  the 
rest  of  the  animal  matter  of  the  world  rolled  into  another 


1  Estimates  not  obtainable. 


288 


CIVIC  BIOLOGY 


ball,  it  is  quite  possible  that  the  Entomostraca  would  be  the 
heavier  of  the  two.^  They  form  the  main  food  of  the  young 
of  fishes  and  many  other  aquatic  animals,  and  also  of  the 
adult  fishes  that  are  provided  with  gill  rakers  —  the  herrings, 
smelts,  shad,  and  others.  They  are  thus  the  connecting  link 
between  the  vast  store  of  floating,  microscopical  plants  and 
animals  (the  primitive  food  supply)  and  all  higher  life  in  the 
water.  Baphnia  and  Cyclops  are  examples  that  may  be  found 
in  almost  any  fresh-water  aquarium  or  in  streams,  ponds, 
and  pools  everywhere.  The  fairy  shrimp  (^Branchipus)  is 
also  found  in  the  icy  pools  of  early  spring. 

The  Lobster  (Homarus  americanus).  Of  the  invertebrates 
used  for  food  the  lobster  ranks  next  in  importance  to  the 
oyster,  and  of  all  marine  animals,  for  the  past  thirty  years,  it 
has  been  m  the  greatest  danger  from  overfishing.  The  reason 
for  this  is  seen  in  the  following  table,  the  supply  having  been 
drained  to  the  utmost  on  account  of  soaring  prices. 


New  ExiiLANi)  Lohstki:  Fishehv 


Ye  All 

Pounds 

Value 

Price  per  Pound 

1880 

19,836,233 
30,449,603 
15,567,081 
14,734,000 
11,504,257 

$473,341 
833,746 
1,362,962 
1,855,000 
2,254,486 

10.024 
0.027 

1890 

1900 

0.088 

1908 

0.125 

1913                  ... 

0.196 

1  The  writer  has  thought,  as  he  steamed  through  a  veritable  slush  of 
copepods  that  colored  the  ocean  for  hundreds  if  not  thousands  of  miles, 
that  here  must  be  the  greatest  of  all  untapped  and  unthought-of  sources  of 
supply  of  animal  matter.  If  the  ship's  engines  could  be  geared  to  some  effi- 
cient filtering  machine,  a  cargo  could  be  secured  as  fast  as  hoisting  and  stor- 
ing machinery  could  handle  it.  The  material  might  prove  as  good,  or  better, 
than  lobster  for  salads  (but  the  microscopic  spines  and  bristles  would  be 
likely  to  interfere  with  human  edibility).  It  might  prove  of  value  for  poultry 
and  swine,  for  oil  production,  and,  at  any  rate,  for  fertilizer.  Perhaps  it 
would  solve  the  problem  of  food  in  fish  hatcheries,  especially  for  marine 
species,  and  make  possible  the  rearing  of  young  lobsters  in  any  quantity. 


CRUSTACEA  289 

Range.  The  American  lobster  ranges  along  the  Atlantic 
seaboard  from  Labrador  to  North  Carolina.  Possibly  no  ven- 
ture in  the  field  of  marine  aqniculture  would  prove  of  greater 
economic  value  than  the  introduction  of  this  species  into  the 
Pacific ;  but  although  egg-bearing  lobsters  have  been  shipped 
across  the  continent  by  thousands  and  in  carload  lots,  up  to 
this  time  all  attempts  of  the  United  States  Bureau  of  Fish- 
eries to  colonize  the  Pacific  have  failed.  While  hiding  among 
the  crevices  of  rocks  would  seem  to  suit  the  habit  of  the 
lobster  best,  it  apparently  thrives  as  well  on  sandy  and  even 
muddy  bottoms,  and  it  ranges  from  the  tide  pools  to  water 
100  fathoms,  or  even  more,  in  depth.^ 

Size,  growth,  and  life  history.  Female  lobsters  spawn  once  in  two 
years;  the  eggs  as  laid  are  cemented  to  the  swimmerets  underneath 
the  abdomen,  and  here  they  are  carried  during  \he  long  incubation 
period  from  July  or  August  of  one  year  till  May  or  July  of  the  next. 
The  hatchlings  —  delicate,  transparent  creatures  about  one  third  of  an 
inch  in  length  —  swim  feebly,  or  rather  "tread  water,"  and  so  tend  to  rise 
toward  the  surface.  They  feed  voraciously  upon  copepods  and  diatoms 
that  they  find  floating  in  the  water,  and  they  eat  one  another  whenever 
they  can  —  a  vicious  habit  which  is  one  of  the  chief  difficulties  in  rear- 
ing them  artificially.  They  swim  thus  for  two  or  three  w^eeks,  growing 
and  molting  three  times  in  the  interval,  all  this  time  at  the  mercy  of 
every  tide,  wave,  and  current  and  of  every  open  mouth  they  may 
encounter.  This  is  the  critical  period  in  the  lobster's  life,  and  probably 
not  one  in  ten  thousand,  under  natural  conditions,  survives  its  accidents 
and  dangers. 

At  the  third  molt  the  young  assumes  adult  form,  and  the  tiny  lob- 
sterling  tends  to  seek  the  bottom  and  may  even  begin  to  burrow  for 
greater  protection.  It  is  now  a  little  over  half  an  inch  in  length,  still  a 
helpless  morsel  for  every  sharp-eyed  minnow.  When  it  is  about  twenty- 
five  days  old,  the  fourth  molt  brings  the  lobsterling  to  the  fifth  stage, 

1  Barnes,  Methods  of  Protecting  and  Propagating  the  Lobster,  E.  L. 
Freeman  Co.,  Providence,  Rhode  Island,  1911.  Refer  to  this  for  further  data 
on  the  habits  and  natural  history  of  the  lobster.  Also,  if.  undertaking 
special  work  on  this  problem,  write  to  Experiment  Station,  Wickford, 
Rhode  Island,  for  up-to-date  information. 


290 


CIVIC  BIOLOGY 


when  the  bottom  habit  is  more  strongly  fixed.  It  is  comparatively  easy 
to  hatch  lobster  eggs,  but  if  the  fry  are  liberated  as  soon  as  hatched, 
nothing  is  gained  over  natural  hatching.  For  about  thirty  years  ex- 
periments have  been  in  progress  in  this  country  to  discover  methods  of 
rearing  lobster  fry  through  the  critical  free-swimming  stages  to  the 
fourth,  or  bottom,  stage.  For  years  results  were  negligible,  but  at  last, 


Fig.  134.    Berried  lobsters,  taken  from  pound  at  Boothbay  Harbor  (Maine), 

in  course  of  transfer  to  wells  of  the  steamer  which  is  to  convey  them  to  the 

hatchery  for  stripping 

United  States  Bureau  of  Fisheries 


in  1910,  by  holding  them  in  floating  cars  the  Wickford  station  was 
able  to  score  a  record  of  8946  fourth-stage  lobsterlings  from  a  counted 
lot  of  10,000  newly  hatched  fry.  The  best  European  result  at  that  date 
was  6.6  per  cent,  beginning  with  1500  in  the  second  stage. 

By  the  end  of  its  first  year  the  young  lobster  has  reached  the  length 
of  2^  inches,  and  not  until  its  sixth  year  does  it  attain  the  respectable 
market  length  of  10  inches.  In  the  usual  effort  to  save  the  lobster 
industry  and  the  species,  laws  have  been  passed  by  the  states  most 
concerned;  but  these  have  not  been  effectual,  on  account  of  lack  of 
knowledge,  and  those  of  different  states  still  conflict  seriously.    Study 


CRUSTACEA  291 

the  lobster  law  in  your  own  state  and  in  neighboring  states  and  discuss 
practical  improvements.^ 

Probably  no  one  has  ever  seen  a  lobster  known  to  be  dead  of  old 
age.  While  specimens  over  15  inches  long  and  weighing  more  than 
2  or  3  pounds  are  now  rare  in  the  markets,  specimens  2  feet  in  length 
and  weighing  10  pounds  were  not  rare  some  years  ago.  The  largest 
lobster  on  record  was  caught  off  the  Xew  Jersey  coast  in  1897.  From 
end  of  chelae  to  tip  of  tail  it  measured  42  inches,  and  it  weighed 
34  pounds.  Growth  has  been  followed  up  to  the  thirty-third  year,  at 
which  time  the  lobster  is  almost  2  feet  long.  If  a  lobster  lives  forty 
years  and  produces  twenty  batches  of  eggs,  averaging  100,000  each,  an 
adult  pair  would  produce  2,000,000  eggs.  This  would  mean,  with  the 
species  holding  its  own  in  the  struggle  for  existence,  that  under  natural 
conditions  only  one  egg  in  a  million  grows  to  become  adult.  If  man 
kills  the  one  that  nature  has  preserved  out  of  the  million  to  keep  up  the 
species,  eggs  and  young  will  fail  and  the  lobster  will  become  extinct. 
Our  laws  are  based  on  the  totally  inadequate  assumption  of  the  fisher- 
men that  if  a  lobster  is  spared  until  it  grows  to  be  10  inches  long  and 
lays  only  one  batch  of  eggs  —  about  10,000  —  the  population  of  the 
species  will  be  maintained.  Both  theory  and  experience  prove  the 
fallacy  of  this  idea. 

Brooks's  law.  We  must  work  out  a  biologically  correct  solution  of 
this  problem  or  lose  our  lobsters.  Dr.  W.  K.  Brooks  ^  has  given  a  dis- 
cussion of  the  problem  as  applied  to  marine  fishes.    This  might  well  be 

1  Rhode  Island  has  led  the  way  by  making  a  closed  season,  from  Novem- 
ber 15  to  April  15.  All  the  states  except  New  York  fine  from  $5  to  $100  for 
killing  an  egg  lobster,  but  the  eggs  are  easily  brushed  off.  Short-lobster  laws 
differ.  In  Maine  a  lobster  must  measure  4f  inches,  body  length  (equal  to 
10^  inches  long) ;  in  New  Hampshire,  10|  inches ;  in  Massachusetts,  9  inches ; 
in  Rhode  Island,  4i  inches,  body  measure  ;  and  in  New  York,  9  inches. 
According  to  the  biologically  correct  view  of  Dr.  Field,  of  the  Massachusetts 
Fisheries  and  Game  Commission,  all  these  short-lobster  laws  protect  the 
wrong  end  of  the  animal's  life.  A  lobster  10  inches  long  produces  10,000 
eggs ;  one  12  inches  long,  20,000 ;  a  16-inch  lobster,  100,000.  The  old  lob- 
ster is  thus  ten  times  as  valuable  to  the  species  for  egg  production,  and, 
being  coarser  and  tougher,  may  not  be  as  valuable  for  food  as  the  legal- 
limit  lobster.  According  to  Field,  lobster  pots  should  be  made  with  open- 
ings too  small  for  the  large  lobsters  to  enter,  S\  or  3^  inches  in  diameter,  and 
with  slats  open  enough  to  permit  all  lobsters  under  a  certain  size  to  escape. 

'-^Brooks,  "The  Artificial  Propagation  of  Sea  Fishes,"  Popular  Science 
Monthly,  Vol.  XXXV  (1889),  pp.  359-367. 


292 


CIVIC  BIOLOGY 


called  "  Brooks's  Law  of  Exterminatiou  of  Sixjcies  by  Mau."    Stated  in 
his  own  words,  this  law  is  "  To  marine  food  fishes  man  is  a  catastrophe. 


not  a  natural  enemy."   This  means 


idult  period, 40(/) 
y years;  2  individ- 
uals, one  pair 


II 

1 


Lobsterling  period, 

\6  years;   200 — >> 

2  individuals 

lAtrvul  {critical) 
period,  1  month ; 
2,000,000  — y  200 
individuals 


Fig.  135.   Diagram  representing  the  indi- 
viduals at  different  stages  in  a  generation 
of  lobsters 

This  is  another  form  of  expression  of  Brooks'  s 
law.  The  typical  form  is  a  pyramid,  with 
a  broad  base  of  eggs  and  young  maintained 
by  a  small  apex  of  adults.  Each  species  of 
animal  or  plant  has  a  form  of  its  own  de- 
pending on  number  of  eggs  and  duration  of 
the  different  stages.  The  large  number  of 
eggs,  the  long  life  of  the  adults,  and  the 
extreme  reduction  of  nmnbers  in  the  short 
critical,  larval  stage  reduces  the  typical 
pyramid  in  the  case  of  the  lobster  to  a 
monument  with  a  broad  base  of  eggs  which 
shrinks  suddenlj'^  during  the  larval  stage  to 
a  slender  spii-e  representing  the  adults 


Man  takes  the  adults  which  natural 
enemies  have  spared  to  con- 
tinue the  species."  Figs.  138 
and  135  show  this  lawdiagram- 
matically  as  it  applies  to  the 
lobster.  It  is  applicable  t^ 
every  species  that  man  attacks, 
from  oysters  and  lobsters  to 
whales  and  pine  trees.  When 
man  disturbs  the  nice  balance 
of  nature  he  must  assume 
control  ("  have  dominion ") 
or  lose  the  species. 

Blue  crab  —  Cattinectes  sapi- 
dus.  This  common  crab  of  the 
Atlantic<'oast  nuirkets  ranges 
from  Massachusetts  Bay  to 
Mexico,  and,  while  it  is  taken 
by  millions  every  year,  shows 
as  yet  no  alarming  signs  of 
decrease.  Two  facts  in  the 
natural  history  of  the  species 
may  largely  account  for  this : 
the  eggs  are  minute,  a  female 
laying  on  the  average  more 
than  3,000,000  at  a  batch ;  and, 
while  molting,  each  female  is 
protected  by  a  hard-shelled 
male. 

Pacific  crab — Cancer  magister. 
This  robust  crab,  7-9  inches 
broad  by  4-5  inches  long, 
ranges  from  Alaska  to  Lower 
California.  In  the  markets  of 
the  Pacific  it  supplies  the  place 
of  both  the  lobster  and  the 
blue  crab  of  the  Atlantic. 
State  laws  are   beginning   to 


CKUSTACEA 


293 


protect  these  crabs  by  making  closed  eeasous  and  by  specifying  size 
limits,  but  the  natural  history  of  this  species  has  not  been  adequately 
studied. 

Crawfish  —  Astacus  (Pacific);  Cambarus  (Atlantic).  Many  species  of 
these  two  genera  inhabit  North  American  fresh  waters  and  lowlands, 
several  of  them  growing  to  6  inches  in  length.  They  are  extensively 
used  for  food  in  P^urope  and  are  growing  in  favor  in  some  parts  of  this 
country.  The  flesh  is  delicate  and  sweet,  like  that  of  lobsters  and  crabs, 
and  there  is  no  good  reason  why  they  should  not  be  much  more  widely 


Fir;.  bSfi.    Female  and  male  crawfish,  the  female  with  eggs 


appreciated  and  utilized.  In  the  waters  they  often  form  the  chief  food 
of  our  game  fishes,  especially  of  the  black  bass. 

Crawfish  are  found  in  the  fresh  waters  of  the  temperate  zones  of  all 
the  continents  except  Africa,  and  it  is  evident  that  they  have  developed 
from  a  number  of  different  marine  forms.  The  largest  crawfish  in 
the  w^orld  is  Astacopsh  frankiimi,  found  in  the  small  streams  along 
the  north  and  west  coasts  of  Tasmania.  These  often  weigh  as  much 
as  9  pounds ;  and  if  they  could  be  safely  introduced,  they  might  give 
us  an  industry  for  our  fresh  waters  that  would  rival  lobster  cidture. 

The  land  crawfishes,  known  as  "  chimney  builders,"  dig  holes  in  soft 
ground,  generally  down  to  water.  These  are  about  an  inch  in  diameter 
and  are  surrounded  by  a  chimney  of  excavated  earth.  This  burrowing 
habit  makes  them  serious  pests  in  embankments  and  levees.  They  are 
also,  in  part,  vegetable  feeders  and  are  often  destructive  to  young  plants 
of  field  or  garden.    A  few  drops  of  carbon  bisulphide  in  a  burrow^  will 


294  CIVIC  BIOLOGY 

kill  the  occupants.  The  Biological  Survey  has  designed  a  special  drop- 
ping can  to  deliver  the  proper  amount,  so  that  extermination  of  craw- 
fish from  land  is  now  quickly  accomplished  with  slight  labor  or 
expense.    Crawfish  are  also  excellent  food  for  poultry. 

The  female  crawfish,  distinguished  from  the  male  by  her  broader 
abdomen,  carries  the  eggs  attached  to  her  swimmerets,  as  do  the  lob- 
sters and  crabs  (Fig.  136),  the  young  passing  through  the  nauplius,  or 
free-swimming,  stage  within  the  shell.  Even  after  hatching,  as  tiny 
crawfish  they  remain  attached  to  the  mother  until  after  the  third 
molt,  when  they  scatter  to  take  care  of  themselves. 

One  or  two  pairs,  kept  in  an  aquarium  or  vivarium  during  the 
hatching  period  (March  to  June),  will  afford  most  valuable  opportu- 
nities for  observing  the  instincts  and  habits  of  a  crustacean.  Per- 
haps some  member  of  the  class  will  volunteer  to  do  this.  If  so,  he 
must  study  carefully  to  make  conditions  as  normal  as  possible,  and 
must  feed  well,  or  they  may  kill  and  eat  each  other,  and  the  females 
may  even  devour  their  own  eggs. 


.       CHAPTER  XXYII  ' 

PROBLEMS  OF  FISH  AND  FISHING 

You  might  have  the  rivers  as  pure  as  the  crystals  of  the  rock,  beautiful 
in  falls,  in  lakes,  and  in  living  pools  —  so  full  of  fish  that  you  might  take 
them  out  with  your  hands.  —  Kuskix 

Now  what  happens  if,  after  each  one  of  the  natural  enemies  has  claimed 
its  victims,  a  new  enemy  not  provided  for  by  Nature  suddenly  attacks  the 
few  adult  survivors  which  Nature  has  provided  to  perpetuate  the  species  ? 
What  happens  when  the  last  drop  falls  into  the  brimming  bucket  ?  What 
happens  when  the  proverbial  last  straw  is  put  on  the  load  ?  It  may  be  quite 
true  that,  for  each  codfish  which  man  catches,  the  natural  enemies  destroy  a 
million.  That  has  no  bearing  on  the  subject.  Nature  has  provided  for  the  de- 
struction of  the  million.  Before  their  birth  they  were  destined  to  premature 
death.  The  one  was  reserved  by  Nature  for  another  purpose. — W.  K.  Brooks 

After  all  that  has  been  said  about  anglers  and  angling,  two  thirds  of  the 
line  fishing  of  the  world  is  done  by  boys.  The  boy  may  fish  with  a  fly,  but 
he  does  not  spontaneously  take  to  this  method.  Fly  fishing  is  an  art,  a  fine 
art  beyond  a  doubt,  but  it  is  an  art  and,  like  all  art,  it  is  artificial.  Fishing 
with  an  angleworm  is  natural.  It  fits  into  the  need  of  the  occasion.  It  fits 
in  with  the  spirit  of  the  boy.  .  .  .  The  angleworm  is  perfectly  at  home  on 
the  hook.  It  is  not  quite  comfortable  anywhere  else.  It  crawls  about  on  the 
sidewalks  after  a  rain,  bleached  and  emaciated.  It  is  never  quite  at  ease 
even  in  the  ground,  but  on  the  hook  it  rests  peacefully,  with  the  apparent 
feeling  that  its  natural  mission  is  performed. —  Holder  and  Jordan,  "Fish 
Stories,"  p.  237 

Civic  problems.  Are  the  waters  of  your  neighborhood 
stocked  with  the  best  fishes  (for  food  and  sport)  that  are 
suited  to  them?  Are  they  supplied  with  such  numbers  as  the 
lakes,  streams,  and  ponds  can  reasonably  support  ?  Are  the 
waters  clean  and  clear,  unpolluted  by  the  wash  of  soil  not 
properly  held  on  the  farms,  where  it  belongs,  by  chemical 
wastes  from  factories,  or  by  sawdust  from  lumber  mills,  so  that 
they  remain  well  adapted  to  the  valuable  fishes  native  to 

295 


296 


CIVIC  BIOLOGY 


them  ?    Do  all  the  people  have  all  the  good  hsh  and  good 
fishmg  they  need  to  keep  them  good-natured  ? 

There  are  millions  of  springs  and  brooks  and  flo\ying  wells, 
many  of  which  might  be  turned  to  good  account  in  forming 
liome  fish  ponds.  These  might  be  made  to  serve  as  storage 
reservoirs  for  irrigation  or  stock  watering,  and  might  be  so 
developed  over  the  country  as  to  help  in  solving  problems 


Fig.  137.    Kxtenninatiiig  shad  fiom  a  Virginia  river 

Largest  seine  in  the  world,  9600  feet  long.  The  seine  was  hauled  hy  steana  power 
and  the  labor  of  80  men.  and  was  drawn  twice  daily,  at  ebb  tide,  throughout  the 
season.  As  many  as  3600  shad  were  taken  at  one  haul,  and  126,000  in  one  season : 
250,000  alewives  were  caught  at  one  time.  The  season's  yield  of  shad  fell  to  300, 
and  the  fishing  w^as  consequently  discontinued  in  1905,  after  having  been  carried 
on  for  a  century.  This  seine  was  a  source  of  eggs  for  the  Bureau's  shad  hatchery 
on  this  river,  Stony  Point,  Virginia.   United  States  Bureau  of  Fisheries 

of  increasing  floods  in  the  river  valleys.  Waste  hollows  and 
ravines  might  be  turned  into  the  most  productive  areas  of 
our  farms,  acre  for  acre,  when  properly  stocked  with  fish. 
Has  this  been  adequately  worked  out  for  the  district?^ 


1  Johnson  and  Stapleton,  "Fish  Pondf 
Bureau  of  Fisheries,  Washington,  lOlo. 


Farms.''  Document  No.  S26, 


PROBLEMS  OF  FISH  AND  FISHING 


297 


If  for  any  district  iii  the  United  States  or  Canada  the  above 
questions  can  be  answered  in  the  affirmative,  there  remains 
still  one  thing  for  the  class  in  civic  biology  to  do.  Write 
up  the  story  to  tell  how  the  community  did  it.  It  will  prove 
the  most  mteresting  and  instructive  ''fish  story"  ever  written. 

Survey  of  district.  The  first  step  toward  a  solution  of  the 
above  problems  is  a  sur- 
vey of  local  waters.  An 
interested  group,  or  com- 
mittee, of  the  class  may 
subdivide  the  district 
among  its  members,  eacli 
of  whom  will  go  over  his 
part  and  make  a  map,  to 
scale,  of  lakes,  streams,  and 
ponds,  along  with  available 
pond  sites,  springs,  and 
flowing  Avells.  Indicate 
stream  flow  by  arrows  and 
depths  by  contour  lines, 
and  adopt  some  uniform 
method  of  showing  areas 
of  vegetation  and  kinds  of 
bottom  —  rocky,  gravelly, 
sandy,  or  muddy.  While 
working  over  the  ground 
in  this  way,  observe  and 
record  condition  of  water.  Is  it  clear  or  nmddy?  Do  sources 
of  pollution  exist  ?  How  might  these  be  remedied  ?  (Con- 
sult state  laws  in  this  connecticm.)  Record  all  fishes  seen, 
and  gather  records,  from  neighbors  and  local  fishermen  and 
markets,  of  the  numbers  and  values  of  the  different  fishes 
taken  during  the  past  season.  This  should  result  in  a  com- 
plete list  of  the  fishes  of  market  value,  with  their  relative 


Fig.  138.   Trial  fishing  on  the  Albatross 

Experimental  catch  of  cod  and  hahbut  taken 
in  twenty  minutes  by  the  Albatross  while  ex- 
ploring? a  new  bank  oif  the  coast  of  Alaska. 
United  States  Bureau  of  Fisheries 


298 


CIVIC  BIOLOGY 


importance,  and  from  these  data  we  should  be  able  to  con- 
struct a  table  showing  the  crop  of  each  kind  of  fish  for  the 
entire  district.  We  may  then  figure  per  acre  production  and 
percentage  of  effective  utilization  of  each  water  unit.^ 

In  making  the  survey,  seek  to  arouse  the  interest  of  the  community. 
Ask  your  fish  experts — the  fish  warden,  the  one  who  has  charge  of 
the  nearest  hatchery,  or  some  of  the  best  local  anglers  —  to  visit  the  class 
and  present  their  views  for  stocking  the  district.  Study  the  publications 
of  your  state  fisheries  commission  and  of  the  United  States  Bureau  of 


/i;  f 


Topography  of  a  fish  (Yellow  perch) 


1,  spinous  portion  of  dorsal  fin ;  2,  soft  portion  of  dorsal  fin ;  3,  caudal  fin;  4,  anal 
fin ;  5,  ventral  fin ;  6,  pectoral  fin ;  7,  opercle ;  8,  branchiostegal  rays ;  9,  mandi- 
ble, or  lower  jaw ;  10,  premaxillary ;  10  o,  maxillary ;  11,  snout ;  12,  eye ;  13,  head ; 
14,  lateral  line ;  15,  series  of  scales,  counting  from  front  of  anal  fin  upward  and 
forward  to  lateral  line 

Fisheries.  Ferret  out  all  such  bulletins  in  private  collections  and  induce 
their  owners  to  loan  or  donate  them  to  the  school  or  public  library ;  and 
write  to  Washington  or  to  your  state  department  for  any  others  that 
may  be  needed. 

1  "It  is  difficult  to  estimate  the  capacity  of  ponds  for  the  various  stages 
in  the  growth  of  fish.  It  depends  for  the  most  part  upon  the  amount  of  ap- 
propriate food  available.  A  2-acre  pond  producing  10,000  one-year-old  black 
bass  from  4  to  6  inches  long  would  be  a  remarkably  successful  enterprise, 
and  20,000  one  and  one-half  to  two  inch  yearling  crappie  or  sunfish  to  an 
acre  of  water  would  be  likewise  notable.  These  numbers  have  been  realized 
and  in  some  instances  exceeded,  but  the  average  results  are  doubtless  much 
smaller." — Johnson  and  Stapleton,  loc.  cit.,  p.  25. 


PROBLEMS  OF  FISH  AND  FISHING 


299 


Finally,  draft  a  plan  for  stocking  and  maintaining  the 
waters  of  the  district  at  their  maximum  production,  and 
have  this  printed  hi  the  local  papers. 

Fishes  Day.^  We  have  Bird  Day  and  Arbor  Day  and 
Apple  Day.  Why  not  have  Fishes  Day  ?  We  ought  to 
know  our  fishes  better.  We  ought  to  know  their  habits  and 
habitats,  their  foods,  and  especially  their  nestmg  and  spawn- 
ing seasons;  and  if  we  did,  it  would  come  to  be  considered 
as  much  an  outrage  to 
take  a  fish  from  her 
nest  as  to  kill  a  mother 
bird  on  hers.  When  we 
all  know  these  things 
and  come,  as  a  whole 
people,  to  have  a  right 
feeling  for  them,  we 
may  then  combine  in- 
telligently to  have  our 
waters  teeming  with  all 
the  best  fishes  they  are 
capable  of  supporting. 

Aquarium  manage- 
ment. This  may  be 
used  as  a  key  to  the  solution  of  our  problems.  A  "  balanced 
aquarium  "  is  one  in  which  just  the  right  proportions  of  animal 
and  plant  life  are  maintained,  with  the  right  amount  of  light, 
so  that  the  water  remains  clear  and  sweet.  This  means  that 
there  are  plants  enough,  under  the  light  admitted  to  the  aqua- 
rium, properly  to  oxygenate  the  water  for  the  animals,  and  ani- 
mals enough  to  supply  the  carbonic  acid  and  nitrogenous  wastes 


Fig.  140.    Bluegill  sunfish  —  best  fish  for 
pond  culture 

Photograph  by  Reighard 


1  Anglers  often  wonder  why  the  fishes  do  not  interest  the  public  as  do  the 
birds,  as  they  are  also  attractive  and  their  habits  interesting,  indeed,  fasci- 
nating. The  reason,  possibly,  is,  that  birds  are  always  in  sight,  while  it  takes 
searching  to  find  the  fishes.  —  Holder  and  Jordan,  "Fish  Stories,"  p.  226 


300  CIVIC  BIOLOGY 

which  the  plants  require  for  healthy  growth.  The  common 
mistake  of  beginners  is  to  overcrowd  the  aquarium  with  both 
animals  and  plants ;  more  waste  matters  are  produced  than 
are  continuously  used,  and  bacteria  develop  and  foul  the  water. 
Too  much  light  is  the  other  common  danger ;  this  results  in 
the  excessive  growth  of  algae,  which  green  the  water  and 
overgrow  the  glass.  A  pond  receives  light  only  from  above, 
while  the  aquarium  may  be  lighted  from  the  sides  as  well. 
Hence  aquaria  do  better  in  north  or  east  windows,  and  even 
here  must  be  provided  with  cardboard  shades  to  shut  out 
almost  all  direct  sunlight  from  the  sides.  South  and  west 
windows  may  be  used  if  three  sides  are  shaded  and  the 
top  partially  shielded  from  direct  sunlight  if  algae  become 
troublesome.  Great  care  must  be  exercised  not  to  overfeed, 
because  uneaten  food  will  decay  and  quickly  fou>  the  water. 
In  an  aquarium  properly  planted  with  good  oxygenators  — 
temperature  of  the  water  not  allowed  to  go  over  15°-18° 
(60°-65°  F.) — two  fishes  3  inches  long  per  gallon  is  the  rule. 
Large  specimens  cannot  be  made  comfortable  in  small  aquaria: 
consequently  small  ones  must  suffice  for  schoolroom  demon- 
stration and  study.  Predacious  fishes  (pickerel,  basses,  and 
sunfish,  eels,  and  all  except  the  smallest  catfishes)  should 
ordinarily  be  kept,  each  kind  and  usually  each  size,  in  a  sepa- 
rate aquarium ;  and  it  will  be  necessary  to  watch  them  and 
to  remove  any  vicious  specimen  or  to  partition  it  off  with  a 
pane  of  glass.  In  equipping  a  laboratory  or  in  planning  an 
exhibition  it  is  better  to  have  a  considerable  number  of  small 
and  medium-sized  aquaria  —  easy  to  set  up  and  each  with  its 
own  distinct  and  clearly  labeled  exhibit  —  than  to  have  a  few 
cumbersome  aquaria  with  impossible  or  difficult  combinations 
mixed  up  in  them. 

The  temptation  is  to  make  aquaria  too  big.    Taking  the  dimensions 
Q-iven  on  page  II,  we  have  the  following  data  for  approximate  capacity 


PROBLEMS  OF  FISH  AND  FISHING 


301 


in  gallons  and  weight  of  water.    Any  size  can  be  figured,  231  cubic 
inches  (weighing  8.34  pounds)  being  a  gallon. 


Si/.i: 

Gallons 

Pounds 

Number  requiked  for  a  Class 
OF  Forty 

fVidth    Jfeiylit     Tftickiu'ss 

5    X      7     X       4  "] 

.66  1 

5.0  "1 

^40  (1  apiece),  used  for  insects, 

8    X    10     X       o    y 
10    X    12     X       0  J 

1.7     I 
3.      J 

12.8   I 
25,     J 

*j  fungi,  and  feeding  tests  with 

Ismail  animals. 

20    X    12     X       U 

0.4 

78.4 

4-1 2,  used  for  demonstrations 

24    X    18     X     12 

22.4 

186.8 

2,  used  for  demonstrations 

Demonstration  aquaria  are  usually  })uilt  into  the  walls  so  as  to  be 
lighted  from  above  and  viewed  through  the  glass  from  inside  the 
room.  This  arrangement  can  be  imitated  by  setting  the  aquaria  on 
suitable  supports  just  outside  the  windows,  on  the  window  sills,  darken- 
ing the  outer  glass  (or  making  the  ends  and  outer  sides  of  slate). 

When  we  begin  to  realize  the  value  of  aquatic  biology,  we  shall  build 
uur  aquaria  into  the  basement  walls,  and  then,  by  proper  placing  and 
grading  of  tlie  building,  we  can  have  abundance  of  room  for  either  still- 
water  or  running-water  aquaria,  under  conditions  as  normal  as  those  of 
natural  ponds  and  streams,  with  which  to  study  all  manner  of  prob- 
lems. If  the  aquaria  were  figured  into  the  original  j^lans,  they  might 
cost  nothing  and  the  basement  walls  might  be  even  less  expensive 
than  the  usual  solid  construction  of  stone  or  brick. 

Our  commissioner  of  fisheries  says  ^  :  "  This  is  a  wide  field ;  I  do 
not  know  of  any  more  promising  field  in  the  government  service  than 
in  the  culture  of  fish.  The  possibilities  of  making  new  discoveries, 
especially  in  the  line  of  intensive  breeding  and  selective  breeding,  are 
almost  inexhaustible.  I  would  expect  that  a  tremendous  boom  to  the 
fish  industry  of  the  entire  country  would  be  given  by  a  fisheries  school 
such  as  this  if  established  here." 

The  still-water  aquarium  is  the  only  kind  recommended  for  ordi- 
nary school  use ;   running  water  is  not  at  all  necessary  for  most  fishes, 

1  H.  M.  Smith,  California  Fiah  and  Game,  Vol.  I  (July,  1915),  p.  189. 
(From  remarks  before  the  Pacific  Fisheries  Society,  Seattle,  on  the  plan  of 
establishing  a  school  of  fisheries  in  connection  with  the  University  of 
Washington  —  on  a  par  with  schools  of  forestry  and  agriculture,  mining 
and  commerce.) 


302 


CIVIC  BIOLOGY 


and  danger  of  a  stoppage  of  escape  pipe,  and  consequent  flooding. of 
building,  is  too  great  a  risk.  The  absolute  rule  should  be  that  one  person 
shall  take  the  sole  responsibility  for  an  aquarium,  and  no  one  else  be  per- 
mitted to  put  anything  in  or  take  anything  out  of  it.  As  long  as  the  aqua- 
rium is  properly  balanced  and  managed,  the  water  need  never  be  changed. 
Water  is  always  water,  and  as  it  evaporates,  clean  pond  or  brook  water 


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r  s 

■^  II 

W    • ' '  i^^S 

¥^M 

^ 

a. 

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dlMl^B^ 

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Fig.  141.    Biological  Laboratory,  Cleveland  Normal  Training  School 

View  of  the  west  end,  showing  three  of  the  four  large  aquaria  built  into  the  wall 
under  the  windows,  and  a  small  greenhouse  opening  out  of  the  laboratory  i 

must  be  added  to  keep  the  level  about  constant.  If  adding  any  consider- 
able quantity,  allow  the  water  to  stand  in  the  room  a  day,  or  until  it  is 
of  the  same  temperature  as  that  in  the  aquarium ;  for  even  small 
changes  of  temperature,  if  sudden,  may  be  injurious,  or  even  fatal,  to 
some  fishes.  The  hand  should  never  be  put  into  the  aquarium  ;  it  carries 
too  many  troublesome  bacteria.  Use  the  proper  tools  —  dipping-tubes  and 
siphons,  dip-nets  and  scrapers.  A  spirit  of  good-natured  rivalry  should  be 

1  The  architect  overruled  the  location  of  these  aquaria  in  the  north  wall 
and  changed  their  specifications.  They  should  be  two  feet,  instead  of  about 
one  foot,  deep,  bringing  the  bottom  two  feet  from  the  floor  and  giving 
double  the  depth  of  water.  The  glass  roof,  if  present  at  all,  should  be  raised 
to  the  middle  bar  of  the  window,  and  the  flap,  which  can  be  lowered  to 
shut  the  space  above  the  aquaria  from  the  room,  should  be  two  feet  wide. 


PROBLEMS  OF  FISH  AND  FISHING 


303 


encouraged,  to  see  who  can  have  the  most  beautiful  aquarium  and  the 
most  instructive  one,  and  hold  it  longest  without  change  of  water.  A  de- 
merit mark  is  deserved,  and  may  be  given,  for  every  time  a  pupil  permits 
the  water  in  his  aquarium  to  become  foul  enough  to  require  changing. 

In  this  way,  by  gaining  experience  through  the  year,  the  students 
may  keep  the  aquaria  running  in  fine  balance,  each  with  some  specimen 
of  native  fish,  and  so  afford  a  most  instructive  exhibition.  This  may  be 
held  in  connection  with  appropriate  lec- 
tures by  specialists  and  a  general  discus- 
sion of  the  plans  which  have  been  worked 
out  for  the  adequate  stocking  of  local 
waters.  Whether  we  call  it  Fishes'  Day 
or  make  it  a  feature  of  more  general  exer- 
cises will  depend  on  community  interests 
and  preferences. 

A  few  important  features  of  such  an 
exhibition  may  be 

1.  Species  of  value  and  relative  impor- 
tance of  each. 

2.  Habits  and  proper  habitats  of  each 
species  (so  far  as  these  can  be  shown  by 
arrangement  of  aquaria). 

3.  Table  of  spawning  seasons ;  pre- 
served specimens  of  eggs  and  fry ;  photo- 
graphs and  other  pictures  of  fish  nests ; 
diagrams  of  local  waters,  with  distribution 
of  nesting  places  of  different  species. 

4.  Eggs  actually  being  hatched  (Fig. 
142)  and  fry  being  fed  and  reared  for 
distribution. 

5.  Foods  of  different  species,  with  natural  food  supplies. 

6.  Extermination  of  mosquitoes  by  fishes,  with  data  from  feeding 
tests  in  the  school  aquaria  and  from  park  or  pond  waters  properly  stocked. 

7.  Data  of  growth  of  different  fishes,  fed  in  different  ways. 

8.  Diagrams  and  records  of  production  of  home  fish  ponds.  (Why 
not  have  fish  projects  and  fish  clubs  as  well  as  corn  clubs  and  pig 
clubs?) 

9.  Enemies  of  different  fishes,  and  means  of  their  control. 

10.  Fish   course,  composed   entirely   of   local  varieties   in    season, 
prepared  by  domestic-science  classes  for  the  exhibit  luncheon. 


Fig.  142.  Tumbler  hatchery 

Water  running  through  funnel 

keeps  eggs  aerated.    Author's 

design 


304  CIVIC  BIOLOGY 

11.  One  or  two  of  the  most  wouderful  curiosities  of  fish  natural  his- 
tory :  a  nest  of  sticklebacks,  "  nothing  short  of  marvelous  "  (Hornaday), 
or  a  paradise  fish  with  his  nest  of  bubbles;  or  exchange  with  coast 
schools  and  devote  one  of  the  large  aquaria  to  artificial  sea  water  and 
marine  forms. 

Classification  and  species.  About  as  many  different  khids 
of  fishes  as  of  birds  are  known  to  science  (13,000,  Galloway), 
but  more  than  four  times  as  many  fishes  as  birds  are  found 
in  the  inland  and  marhie  waters  of  North  America  (3263 
species).^  Any  list  (published  by  your  state  fish  commission 
or  by  the  United  States  Bureau  of  Fisheries)  giving  the  dis- 
tribution of  fish  and  fish  eggs  for  the  preceding  year  will 
contahi  about  fifty  of  the  more  valuable  food  and  game 
species,  and  from  this  we  may  choose  the  most  instructive 
types  for  study.^ 

Ponds  as  balanced  aquaria :  foods  and  overstocking.  The 
work  with  aquaria  may  be  made  to  help  in  understanding- 
how  to  keep  park  waters  and  reservoirs  in  good  condition. 
Lack  of  proper  balance  results  in  foulmg  the  water,  and 
is  accompanied  with  offensive  odors  and  appearance.  The 
fishes  die,  beginnmg  with  the,  more  overcrowded  or  more 
sensitive  kinds,  and  ending  with  the  catfishes,  which  can  live 
in  fairly  wholesome  mud.  Probably  in  most  such  cases  the 
prime  reason  why  the  fishes  die  is  because  they  lack  proper 

1  Jordan  and  Evermann,  Descriptive  Catalogue  of  North  American  Fishes, 
3313  pages,  392  plates.  "The  work  has  been  carefully  devised  to  be  of  no 
use  whatever  to  anyone  save  an  ichthyologist''  (Hornaday). 

2  The  list  recommended  for  pond  culture  is  as  follows :  black  basses 
(small-mouthed  and  large-mouthed),  crappie,  calico,  rock,  and  warmouth 
basses,  the  bluegill  sunfish,  and  the  catfish,  or  bullhead  (either  Ameiuriiti 
nebulosus  or  A.  n.  marmoratus,  a  variety  known  in  the  South  as  the  marble 
cat).  Strong  local  prejudice  and  lack  of  outward  beauty  are  against  the 
humble  catfish,  but  for  edibility  Dr.  Jordan  has  placed  it  above  all  the 
basses,  perches,  and  pikes,  and  just  below  the  trout,  salmon,  and  whitefish. 
The  bluegill  is  the  only  sunfish  recommended  for  use  by  the  Bureau  of 
Fisheries,  ''and  it  is  believed  to  be  the  finest  pond  fish  available  for  private 
culture." — JouNsox  and  Statlktov,  loc.  cit.,  p.  18. 


PliOBLEMS  OF  FISH  AND  FISHING 


805 


food;  that  is,  if  they  were  thriving  and  growing,  they  would 
resist  attacks  of  saprolegnia  or  other  disease  germs.  A  variety 
of  plants  and  animals  is  essential  in  a  balanced  pond  if  it  is 
to  supply  food  continuously  to  all  its  inhabitants.  As  witli 
similar  problems  on  land,  the  most  necessary  thing  is  an 
abundance  of  plants,  to  supply  food  for  snails,  mussels,  in- 
sects, worms,  Crustacea,  and  vegetable-feeding  fishes;  then 
mussels  should  be  present  in  sufficient  numbers  to  strain  out 
any  excess  of  floating 
algse  and  fungi ;  and, 
finally,  there  nmst  be 
enough  carnivorous 
forms  to  prevent  exces- 
sive multiplication  of 
the  vegetarians.  Of 
course  this  natural  bal- 
ance of  lakes  and  ponds 
is  a  more  complex  mat- 
ter than  that  of  our 
aquaria,  since  these  are 
never  required  to  pro- 
duce all  the  foods  of 
the  fishes. 


Fig.  143.  Tray  of  wild-trout  eggs,  with  mos- 
quito net  and  moss  in  which  they  were  packed 

United  States  Burea\i  of  Fisheries 


Even  good-size<l  lakes 
may  lose  balance,  and  cer- 
tain species  may  suffer.  The  white  bass  in  Lake  Mendota,  Wisconsin,  in 
the  summer  of  1889,  died  in  such  numbers  that  windrows  of  them  were 
washed  upon  the  shores,  necessitating  the  removal  of  over  200  wagonloads 
from  the  mile  or  so  of  beach  in  Madison.  They  had  become  overcrowded 
and  weakened  by  starvation.  Lake  Louise,  in  Pennsylvania,  was  stocked 
with  black  bass,  and  the  rules  of  the  fishing  club  that  controlled  it  required 
that  all  the  fish  caught  be  returned  to  the  lake.  In  a  few  years  the  lake 
had  nothing  but  black  bass  in  it,  and  these  were  so  starved  that  the 
fish  were  almost  all  heads  and  mouths,  with  shrunken  bodies.  The  case 
was  investigated  l^y  the  United  States  Bureau  of  Fisheries,  which 
advised  fishing  out  the  surplus  black  bass  and  transferring  them  to  the 


306  CIVIC  BIOLOGY 

Susquehanna  River,  where  there  was  abundance  of  food,  and  introducing 
food  fishes  (perch,  minnows,  and  crawfish)  and  aquatic  insects.  The 
starved  black  bass  very  soon  grew  to  proper  form  when  well  fed. 

Food  being  practically  the  limiting  factor,  self-sustaining  ponds  are 
said  to  be  capable  of  producing  from  5000  to  6000  pounds  of  fish  per  acre.^ 
This  yields  a  cash  value,  at  10  cents  per  pound,  of  from  $500  to  $600, 
"  and  this  with  no  expenditure  for  food."  No  figures  are  available  for 
limits  of  possible  production  in  well-planted  and  aerated  ponds  if  the 
fish  are  given  adequate  variety  and  quantity  of  food.  Estimates  might 
prove  more  amusing  than  instructive.  For  example,  in  a  self-feeding 
pond  of  one  acre,  3  feet  deep,  we  have  130,680  cubic  feet  of  water.  At 
5000  pounds  per  acre,  we  should  have  1  pound  of  fish  produced  in  about 
26  cubic  feet  of  water.  Suppose,  by  proper  care  and  feeding,  we  could 
produce  1  pound  per  cubic  foot  (7.48  gallons)  ?  Can  anyone  so  feed  and 
care  for  a  bluegill  or  a  catfish,  in  a  five-gallon  aquarium,  that  it  will  gain 
1  pound  in  a  year? 

Successful  combinations  in  aquaria  may  suggest  similar  treatment  of 
ponds.  That  is,  can  anyone  manage  and  feed  a  bluegill  and  a  catfish 
in  the  same  five-gallon  aquarium  so  that  each  will  gain  a  pound  in  a 
year?  Thus  we  see  that  by  learning  the  habits  and  preferred  habitats 
of  different  fishes  we  may  have  all  parts  of  our  pond  occupied  and  so  in- 
crease production.  The  pout  will  choose  the  stagnant  holes  with  muddy 
bottoms ;  the  perch,  the  deeper  channel,  where  there  is  some  current ; 
the  crappies,  rock  bass,  and  sunfish,  the  shelter  of  stumps  and  brush  and 
weed  patches.  The  water  will  be  purified  if  the  bottom  is  well  stocked 
with  the  best  available  mussels,  and  crawfish  (if  there  is  no  danger  from 
their  burrowing)  may  do  the  scavenging  and  turn  waste  matters  into 
food  for  the  fishes.  Frogs  and  toads,  if  allowed  to  breed,  may  further 
help  in  the  balance  of  life ;  and,  finally,  a  few  pairs  of  mallards,  teal,  or 
wood  ducks  might  fit  in,  both  for  ornament  and  for  profit.^ 

1  N.  R.  Buller,  ''What  an  Acre  of  Water  Will  Do,''  Bulletin  No.  10, 
Pennsylvania  Department  of  Fisheries,  1914,  p.  7. 

2  In  a  project  of  this  kind,  like  working  for  a  record  production  of 
com,  potatoes,  or  poultry,  we  open  a  new  field  of  interesting  possibilities. 
Who  can  produce  the  largest  and  best-balanced  and  most  varied  crops  from 
an  acre  of  water  ?  Water  cress,  water  lilies  (of  many  rare  and  beautiful 
kinds),  cowslips,  gentians,  and  cardinal  flowers,  the  fishes,  frogs,  crawfish, 
possibly  fingerlings  for  distribution,  perhaps  a  ton  or  so  of  highest-grade  mus- 
sel shells,  and  a  fine  flock  of  wild  ducks  for  distribution  and  propagation  — 
will  results  from  such  a  home-pond  project  bear  out  the  statement  that  "an 
acre  of  water  may  be  made  to  produce  as  much  as  five  acres  of  land  "  ? 


PROBLEMS  OF  FISH  AND  FISHING  307 

A  record  at  the  end  of  a  successful  year  might  read  somewhat 
as  follows : 

Record  Production  from  a  Pond  of  One  Acre,  from 
One  to  Ten  Feet  Deep 

3000  pounds  catfish $300.00 

3000  pounds  bluegills 300.00 

5000  fingerling  catfish,  removed  in  fall  to  thin  stock  ....  50.00 

5000  fingerling  bluegills,  removed  in  fall  to  thin  stock    .    .    .  25.00 

12  dozen  frogs 6.00 

50  dozen  crawfish 10.00 

1  ton  yellow  and  green  striped  mucket  shells 80.00 

50  wood-ducks'  eggs,  early 12.50 

3  pairs  wood  ducks 45.00 

1000  bunches  water  cress  —  from  clean,  fenced  intake  stream  50.00 

100  dozen  water  lilies 10.00 

100  dozen  cardinal-flower  spikes 10.00 

10  bushels  cowslip  greens 4.00 

1000  pounds  basket  willows  —  from  margins  and  island  .    .    .  50.00 

Total 1952.50 

Seeds,  tubers,  bulbs,  and  plants  of  acjuatic  duck  foods,  any  of  which, 
if  present  in  excess,  might  be  made  to  increase  the  account,  are  quoted 
in  a  price  list  as  follows  : 

Duck  potato,  or  wapata  {Sagittaria  latifolia):  bulbs,  15  cents  each;  $5 

per  100. 
Wild  celery  {Vallisneria  spiralis)  (must  be  wet):  35  cents  per  pound. 
Water  cress  {Nasturtium  officinale):  plants,  10  cents  each;  $4  per  100; 

$20  per  1000  ;  seed,  50  cents  per  ounce  ;  |5  per  pound. 
American  lotus  lily  {Nelumbo  lutea) :   tubers,  f  1  each ;  flO  per  dozen ; 

seeds,  |1  per  100. 
Wild  rice  {Zizania  aquatica)  (must  be  wet):  seed,  35  cents  per  pound. 
Potamogetons  (mixed):  fl  per  quart ;  |20  per  bushel. 
Wild  sago  {Potamogeton  pectinatus):  |1  per  quart ;  $25  per  bushel. 
Musk  grass  {Chara)  (mixed  or  single  species):  $7.50  per  crate. 
Duckmeat  (Lemna):  |1  per  quart ;  |10  per  dozen  quarts. 
Anacharis,  or  Elodea  {Philotria  canadensis):  $6  per  crate. 
Coontail,  or  hornwort  {Myriophyllum)  (various  species):  |7.50  per  crate. 

To  this  list  we  might  add  : 

Cardinal  flowers  {Lobelia  cardinalis),  seeds  and  plants. 

Water  lilies  {Castalia  or  Nelumbo)  (various  species),  seeds  and  rootstocks. 


308 


CIVIC  BIOLOGY 


Professor  Forbes  of  the  Uuiversitj  of  Illinois  has  made  a  special 
study  of  the  foods  of  fishes.  He  has  found  that  with  most  fishes  foods 
change  with  age,  the  life  of  a  fish  being,  in  fact,  divided  into  two  and 
often  three  distinct  jieriods.  In  the  first,  which  we  may  call  the  "  fry  " 
period,  from  hatching  to  one  or  two  inches  in  length,  all  species  feed 
on  small  Crustacea.  In  the  fingerling  stage,  from  one  or  two  to  four 
inches,  they  feed  largely  on  insects  but  begin  to  devour  their  smaller 
fellow  fishes  as  well.    When  adult,  the  larger  species  feed  chiefly  upon 


Fig.  144.    Visiting  Municipal  Fish  Market,  Cleveland,  Ohio 
Class  learu  to  distinguish  fresh  iisli  by  the  red  gills  and  the  uusiinkeu  eyes 

smaller  fishes,  while  tlie  smaller  s[>ecies  continue  to  feed  mostly  on 
insects.  Adult  fishes  possessing  fine  gill  rakers  continue  to  strain  out 
the  minute  Crustacea;  those  with  heavy,  blunt  teeth  feed  largely  on  mol- 
lusks;  and  worms  play  but  a  small  part  in  the  food  of  fresh-water  fishes. 

Spawning  habits  and  seasons.  Brooks's  law,  as  stated  in  its 
application  to  the  lobster,  with  the  diagrams  illustratmg  it, 
applies  with  equal  force  to  food  and  game  fishes.  With  the 
powerful  machinery  at  his  disposal,  man  strikes  all  species 
as  a  catastrophe  and  not  as  their  natural  enemy ;  and  he 
must  make  good  his  attack  by  intelligent  dominion  or  lose 


PKOBLEMS  OF  FISH  AXD  FISHIXG 


309 


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BIO  CIVIC  BIOLOGY 

the  species.  The  large  numbers  of  eggs  produced  by  fish 
indicate  how  quickly  we  may  have  our  waters  abundantly 
stocked,  as  soon  as  we  learn  enough  to  cooperate  in  leaving 
a  sufficient  number  of  adult  spawners  and  in  insuring  protec- 
tion of  eggs  and  young  from  their  natural  enemies.  The  data 
in  this  field  must  be  worked  out  in  connection  with  the  local 
surveys  suggested  above.  The  table  above  is  offered  merely 
by  way  of  further  suggestion.  The  biology  class  in  each  district 
should  have  its  own  table,  developed  to  give  local  dates  and 
precise  breeding  places,  so  that  all  may  know  how,  when,  and 
where  to  protect  effectively  all  valuable  species  during  their 
spawning  seasons.  This  knowledge  may  be  of  advantage  in 
exterminating  pest  species,  such  as  garfish  and  dogfish. 

Economic  and  civic  values.  To  doubt  the  value  of  fish 
culture  would  be  as  absurd  as  to  question  that  of  agri- 
culture. For  the  United  States,  including  insular  posses- 
sions, an  invested  capital  of  $79,000,000,  with  about  165,000 
people  employed,  results  in  gathering  a  food  product  amount- 
ing to  191,073,000  annually.  The  fishes  do  most  of  the 
work,  foraging  in  the  boundless  food-wealth  of  the  ocean  and 
then,  like  the  shad,  salmon,  and  others,  bringing  it  up  our 
rivers  and  to  our  very  doors.  As  the  cost  of  food  advances, 
we  are  beginning  to  ask  what  are  the  possibilities  of  supply 
from  our  waters.  The  brief  table  on  the  next  page  may  serve 
to  indicate  the  problem  for  the  species  named. 

Sport  fishing  also  carries  civic  values  and  yields  annual 
returns,  not  only  in  catch  but  in  health  and  pleasure,  of 
possibly  no  less  importance  to  the  country  as  a  whole  than 
the  commercial  fisheries.  It  gives  employment  to  thousands 
in  the  manufacture  of  tackle  and  boats,  stimulates  travel,  and 
supports  many  special  outing  resorts.  Is  not  good  fishing 
an  asset  to  any  community,  well  worth  careful  study  and 
conservation  ? 


PROBLEMS  OF  FISH  AND  FISHING 


311 


Shad,  Atlantic  .  .  . 
Shad,  Pacific  .  .  .  . 
Salmon,  Atlantic  .  . 
Salmon,  Pacific  .  .  . 
Total  fresh-water  fish 


Value  of  Present 
Yearly  Catch 


$2,085,200 

22,000 

3,700 

3,342,700 

12,000,000 


Value  of  Possible 
Yearly  Production^ 


1  This  table  was  submitted  to  the  United  States  Bureau  of  Fisheries,  but 
no  estimates  were  available.  Dr.  George  W.  Field  estimates  that  under 
proper  management  the  marine  and  fresh  waters  of  Massachusetts  might 
be  made  to  yield  f 50,000,000  worth  of  products  annually. 


Fig.  145.   Toad  catching  ants 
Photograph  hy  Newton  Miller 


Fig.  146.   Toad  exposed  in  its  hibernation  cavity 

Note  protective  coloration  and  granulation  of  skin  in  relation  to  earth. 

Photograph  by  Newton  Miller 

312 


CHAPTER  XXVIII 

AMPHIBIA:    SIRENS,    PROTEANS,    SALAMANDERS,    FROGS, 
TREE   FROGS,  AND  TOADS 

For  an  insectivorous  animal  which  conforms  to  every  requirement  of  the 
situation  —  ease  of  control  and  rapid  increase,  noninjurious  in  any  numbers, 
an  active  feeder  in  abundance  and  a  patient  faster  in  scarcity  —  the  toad 
stands  probably  first  on  the  list  among  American  insectivorous  animals. — 
Miller,  "Biology  of  the  American  Toad,"  American  Naturalist^  Vol.  XLIII 
(1909),  p.  643 

The  amphibia  are  a  relatively  small  group  of  about  1400 
species,  of  div^erse  kinds  (from  wormlike  Ccecilians,  through  the 
two-legged  and  four-legged  sirens  and  salamanders,  to  frogs 
and  toads)  —  aquatic,  semiaquatic,  and  terrestrial  —  form- 
ing, as  the  name  implies,  a  transition  series  from  the  fishes 
to  the  higher  land  animals.  All  amphibia  are  carnivorous, 
many  of  our  common  forms  ranking  with  birds  as  efficient 
destroyers  of  insects  ;  and  as  a  group  they  cover  the  whole  field, 
for  salamanders,  bullfrogs,  and  other  aquatic  species  hunt  the 
waters  of  our  ponds  and  streams  and  their  immediate  shores, 
wood  frogs  and  toads  and  many  of  the  salamanders  follow 
insects  of  the  ground  both  by  day  and  by  night,  and  tree 
frogs  are  especially  adapted  to  feeding  upon  insects  of  forest 
and  orchard.^ 

Amphibia  belong  exclusively  to  fresh  waters  and  the  land. 
They  are  comparatively  small,  the  largest  modem  amphibian 
being  the  giant  salamander  of  Japan,  which  is  said  to  reach  a 

1  Hornaday's  statement,  ''  With  very  few  exceptions,  the  amphibians  are 
quite  useless  to  man  "  (Natural  History,  p.  360),  is  evidently  made  without 
due  regard  to  their  powers  of  insect  destruction  or  even  to  their  uses  as 
fish  bait. 


314 


CIVIC  BIOLOGY 


Fig.  147.   Laying  cf  a  toad  — 15,835  eggs 
Photograph  by  Newton  Miller 


length  of  6  or  7  feet.    Gigantic  species  formerly  disported  in 

the  vast  swamps  that  have 
given  us  our  coal  forma- 
tions. With  few  exceptions, 
amphibia  deposit  their  eggs 
in  water,  and  they  all  pass 
through  a  truly  larval  stage, 
the  "  tadpoles  "  being  fish- 
like— aquatic,  legless,  and 
breathing  by  gills.  In  ad- 
dition to  insect  destruction 
by  the  adults,  the  tadpoles 
perform  an  important  serv- 
ice by  eating  all  manner 
of  slimes  and  scums  and 

decaying  animal  and  vegetable  matter,  thus  helping  to  purify 

surface  waters.     Aquaria  with  and  without  tadpoles  may  be 

made  to  demonstrate  this 

point  in  a  strikmg  manner, 

and  the  results  may  well 

be  applied  to  the  problem 

of  cleansing  local  park  and 

reservoir  waters. 

Natural  history  of  local 

species.  In  connection  with 

other  outdoor  work,  collect 

all    the    different    species 

of  toads,  frogs,  tree  frogs, 

newts    and     salamanders, 

mud   puppies,   and   sirens 

common    to    the    locality. 

Special  interest  attaches  to 

spawning  habits  and  sea- 
sons,  since   knowledge  of 


Fig.  148.     Different  portions  of  single 
laying  of  toads'  eggs 

The  top  specimen  shows  the  usual  arrange- 
ment; the  other  two  show  the  crowding 
and  irregular  spacing  of  the  eggs  in  the 
gelatinous  tube  near  the  end  of  the  laying. 
Photograph  by  Newton  Miller 


AMPHIBIA 


315 


these  data  will  enable  a  community  to  give  effective  protec- 
tion to  valuable  species.  Frogs  and  toads  proclaim  this  sea- 
son, each  species  with  its  own  peculiar  note,  from  the  earliest 
shrill  whistles  of  the  spring  peepers,  and  the  croaks,  clucks, 
trills,  and  warbles  of  the  frogs,  toads,  and  tree  frogs,  to  the 
bass-viol  br-wums  and  jug-o-rums  of  the  bullfrogs  in  late 
June  and  early  July.  The  eggs  are  most  interesting  forms 
with  which  to  follow  embryological  development,  and  their 
numbers  indicate  possi- 
bilities of  increasing  val- 
uable species,  when  we 
learn  to  provide  favor- 
able conditions.  The 
toads'  eggs  are  found  in 
strings ;  the  green  frogs' 
and  bullfrogs',  in  loose, 
floating  films ;  the  wood 
frogs',  leopard  frogs',  and 
pickerel  frogs',  in  globu- 
lar masses  of  jelly;  and 
the  peepers',  single  or  in 
small  clusters.    Observa- 


FiG.  149.  Toad  tadpoles  as  scavengers,  eat- 
ing dead  pout  at  margin  of  pond 
Photograph  by  Newton  Miller 


tions  by  the  class  may  yield  a  table  for  local  species  some- 
what like  the  one  shown  on  the  following  page. 

The  feeding  test.  Amphibia  afford  most  convenient  ani- 
mals with  which  to  study  foods  and  feeding  habits.  Imitate 
natural  habitats  in  the  arrangement  of  terraria  and  aquaria  — 
moist  earth,  moss,  or  sod  for  toads,  wood  frogs,  and  land 
salamanders,  with  a  forked  branch  and  a  small  pool  for  tree 
frogs,  and  a  larger  pool,  with  a  bank  of  moss  at  one  end,  for 
aquatic  frogs  and  salamanders.  Then,  for  the  tests,  introduce 
all  sorts  of  insects,  spiders,  millepeds,  crustaceans,  slugs,  and 
worms,  counting  the  numbers  and  kinds  eaten.  No  single 
laboratory  exercise  shows  so  convincingly  the  value  of  the 


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CIVIC  BIOLOGY 


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AMPHIBIA  317 

work  of  a  species.  Different  members  of  the  class  may  take 
different  species,  and  the  data  obtained  should  be  applied  to 
solving  the  insect  problems  of  the  locality. 

Almost  all  insects  come  to  the  ground  at  some  time, 
and  we  have,  especially  in  the  toads,  a  possible  force  of  insect 
police  that  ought  to  be  better  known  and  utilized. 

Commercial  values.  Toads  are  regularly  sold  in  the  markets  of  Europe, 
being  used  by  gardeners  to  control  insect  pests.^  Is  there  any  local  mar- 
ket for  them?  Could  such  a  market  be  developed  as  a  result  of  studies 
and  demonstrations  to  prove  their  value?  The  following  numbers  of 
insects  have  been  eaten  by  a  toad  at  a  meal  or  were  found  in  a  toad's 
stomach :  90-100  rose  beetles  (Pollen  M.  Foskett) ;  55  army  worms,  77 
myriapods,  65  gypsy-moth  caterpillars  (A.  H.  Kirklaud,  in  three  stom- 
achs) ;  24  gypsy-moth  caterpillars  (fourth  molt),  taken  in  ten  minutes 
(Wilcox);  86  house  flies,  snapped  up  in  less  than  ten  minutes  (Hodge). 
From  examination  of  149  stomachs,  Kirkland^  estimates  that  a  toad  will 
eat,  in  the  three  months  of  May,  June,  and  July  (why  he  does  not  in- 
clude August  and  September  is  not  stated ;  these  months  would  add 
materially  to  the  account),  .3312  ants,  2208  cutworms,  1840  myriapods, 
2208  sow  bugs,  368  weevils,  and  368  carabid  beetles.  Subtracting  the 
cutworms  that  might  have  been  killed  by  the  carabids,  we  have  1988  cut- 
worms to  the  toad's  credit.  He  estimates  the  killing  of  these  as  worth 
one  cent  a  piece  to  a  gardener,  and  thus,  for  cutworms  alone,  the  possi- 
ble value  of  the  toad's  work  is  $19.88  for  the  season.  Miller  ^  is  more 
conservative  and  estimates  a  toad's  work  for  a  season  at,  possibly,  about 
$5  "for  greenhouses,  gardens,  and  truck  farms"  and  not  so  much  in 
ordinary  farming  districts. 

Frogs,  especially  bullfrogs,  are  much  more  inclined  to  feed  ujkju  ani- 
mals other  than  insects  —  fish,  birds,  crawfish,  and,  above  all  else,  upon 
other  frogs.  This  is  the  great  obstacle  to  frog  culture  —  except  on  paper. 
No  matter  how  many  we  succeed  in  bringing  through  the  tadpole  stage, 
we  have  few  big  frogs  in  the  end.  The  difficulty  in  feeding  frogs  arti- 
ficially is  that  they  take  only  active,  moving,  hence  living,  food.  It  would 

1  Kirkland  states  {Farmers''  Bulletin  No.  196,  p.  14)  that  English  gardeners 
pay  |25  per  hundred. 

2  Kirkland,  Hatch  Experiment  Station,  Bulletin  46  (1897),  p.  27. 

8  Miller,  ''  The  American  Toad,"  American  Naturalist,  Vol.  XLIH  (1909), 
p.  668. 


318 


CIVIC  BIOLOGY 


seem  entirely  possible  to  solve  the  problem  of  supplying  such  foods  in 
quantity  and  variety  that  would  largely  prevent  even  the  bullfrogs  from 
eating  each  other.  We  might  have  lighted  insect  traps  to  deliver  their 
catches  of  moths  and  beetles  all  night  long  into  the  water  beneath  them ; 


EiG.  150.  Toad  tadpoles  (broad,  dark  margin  of  pond);  young  toads  emerged 
and  moving  landward  (irregular  gray  edge  of  shore) 

Photograph  by  Newton  Miller 

sweeps  designed  to  catch  grasshoppers  alive ;  blowfly  maggot  hatcheries, 
made  to  drop  the  maggots  into  the  water  as  they  ripen ;  or,  if  all  these 
should  not  suffice,  crawfish  and  the  smaller  species  of  frogs  could  be 
added.    Meehan^  states  that  "30,000  tadpoles  have  been  safely  carried 

1  Meehan,    "Possibilities  of  Frog  Culture,"   Country  Life  in  America 
(1908),  p.  315. 


AMPHIBIA 


319 


Fig.  151.  Common  tree  frog 

Photograph  by  Millett  T. 
Thompson 


to  frogdom  in  a  pond  30  feet  by  15,  having  a  depth  of  2  feet  of  water." 
As  eggs  of  leopard  frogs,  pickerel  frogs,  and  wood  frogs  can  usually  be 

gathered  in  any  desired  quantity,  this  would 
indicate  almost  unlimited  possibilities  of 
live-food  production. 

In  addition  to  their  uses,  actual  and 
potential,  as  insect  traps,  frogs  have  com- 
mercial values  which  threaten  their  exter- 
mination in  many  localities.  In  some  places 
small  ones  bring  from  $1  to  |2.50  per  100 
for  fish  bait.  The  frog  is  the  animal  most 
commonly  used  for  laboratory  study  the 
world  over ;  frogs  used  for  this  purpose 
bring  from  50  cents  to  $3  per  dozen.  More- 
over, while  they  were  rarely  used  for  food 
a  few  years  ago,  frogs'  legs  have  now  be- 
come a  well-known  delicacy.  "The  meat 
is  white,  delicate,  and  very  wholesome  and 
palatable."  Hence  catching  frogs  for  mar- 
ket often  yields  good  profit,  and  it  affords  a  mildly  humorous  form  of 
outdoor  sport.  As  these  values  come  to  be  recognized,  valuable  species 
can  be  protected  by  closed  seasons  (from  the  opening  of  spring  until 
after  they  spawn),  local 
waters  can  be  kept  stocked 
to  their  full  capacity,  and 
an  abundant  crop  can  be 
secured  each  year. 

Some  special  problems. 
1.  In  a  pond  stocked  with 
bullfrogs,  how  can  we  feed 
so  as  to  prevent  cannibal- 
ism and  thus  secure  the 
greatest  number  of  large 
specimens  from  a  given 
area? 

2.  How  can  the  largest  number  of  toads  be  reared  from  a  pool  a  foot 
square  and  a  foot  deep?  (We  have  one  record  of  3938  from  April  to 
August ;  the  main  foods  were  algae,  dog  biscuit,  and  fresh  fish.) 

3.  Are  toads  being  exterminated  from  agricultural  districts  by  drain- 
ing their  breeding  pools,  by  farm  animals,  and  by  the  operation  of  farm 


Fig.  152.   Pair  of  spotted  salamanders 
Photograph  by  Millett  T.  Thompson 


320 


CIVIC  BIOLOGY 


machinery?  Could  this  be  prevented?  If  so,  how?  Might  it  be  worth 
while,  as  a  measure  for  insect  control,  to  try  the  experiment  of  stocking 
a  farm  with  them,  and  comparing  the  damage  done  by  insects  on  such 
a  farm  with  that  on  a  similar  farm  where  there  are  no  toads? 

Elementary  classification  and  distribution.  The  names  at  the  head  of 
this  chapter  present  the  main  groups  of  amphibia  in  ascending  order. 

They  are  placed  there  to  serve 
as  handles  by  which  any  form 
that  is  of  local  interest  or  im- 
portance may  be  looked  up 
in  the  dictionaries,  natural 
histories,   or  zoologies. 

Jordan's  "  Manual  of  Ver- 
tebrates "  describes  eighty-one 
species  of  salamanders  for  the 
United  States.  So  little  is 
known  about  their  habits, 
foods,  spawning  seasons,  and 
general  natural  history,  that 
they  offer  an  almost  virgin 
field  for  young  American  nat- 
uralists —  a  field  that  needs 
working  the  more  on  account 
of  senseless  prejudices  con- 
cerning the  venomous  char- 
acter of  these  harmless  and  valuable  animals.  The  mud  puppy 
(Nectuj'us  maculosus)  of  the  upper  Mississippi  and  Great  Lakes  basins 
destroys  the  sj^awn  and  young  of  fishes,  but  this  is  the  only  one  of  the 
tailed  amphibia  that  is  considered  harmful. 

Recent  books  describe  fifty-three  species  of  the  tailless  amphibia  as 
native  to  the  United  States  —  the  frogs,  tree  frogs,  and  toads.  Of  the 
fourteen  species  of  toads  the  greater  number  occur  in  Texas  and  south- 
western United  States,  indicating  this  region  as  the  probable  center 
from  which  the  group  has  spread  over  the  continent. 


Fig.  153.    Coast  newt  depositing  eggs  in 
an  aquarium 

Photograph  by  Loye  Holmes  Miller 


CHAPTER  XXIX 

REPTILES:   CROCODILES,  ALLIGATORS,  TURTLES, 
TERRAPINS,  TORTOISES,  LIZARDS,  SNAKES 

However,  the  Reptilia  take  up  a  very  central  position  in  the  evolution 
of  the  main  classes  of  the  Vertebrata.  On  the  one  hand,  there  is  not  the 
slightest  doubt  that  they  are  evolved  from  some  branch  of  the  Stegocephali, 
whilst  on  the  other  hand  the  reptiles,  probably  through  some  branch  of 
the  Theromorpha,  have  given  rise  to  the  mammals ;  some  other  reptilian 
branch,  at  present  unknown,  has  blossomed  out  into  the  birds. —  Hans 
Gadow,  "Cambridge  Natural  History,"  A^ol.  VIII,  pp.  277-278 

In  the  absence  of  birds,  what,  then,  holds  the  devastating  hosts  of 
insects  in  check,  for  insects  abound  in  all  warm  countries  where  vegeta- 
tion is  luxuriant  ?  This,  in  my  opinion,  is  the  lizard  brigade,  —  those 
spry  and  cheerful  little  fellows  in  brown  "homespun,"  of  which  La- 
certa  muralis  is  the  commonest  kind,  which  are  seen  streaking  it  over  walls 
and  along  the  ground,  in  town  and  country  everywhere.  —  F.  H.  Her- 
RiCK,  "  Italian  Bird  Life  as  it  impresses  an  American  To-day,"  Bird  Lore, 
Vol.  VIII,  p.  196 

Why  may  not  a  good  snake  merit  the  same  protection 
as  a  good  bird  ?  The  reason  is  that  we  have  not  taken  the 
pains  to  know  the  good  from  the  bad,  and  our  prejudice 
and  fear,  the  children  of  ignorance,  have  dominated  the  field. 
As  venomous  snakes  have  been  almost  exterminated  from 
inhabited  parts  of  tlie  country,  we  are  coming  to  be  able  to 
appreciate  the  beauty  and  acknowledge  the  good  there  may 
be  even  in  a  snake.  In  general  a  reptile  is  a  good  citizen 
if  it  does  good  work  in  the  world,  if  it  feeds  upon  injurious 
insects  or  upon  rats  and  mice  or  other  harmful  animals,  and 
if  it  is  not  venomous.  In  addition  to  this  larger  aspect,  a 
number  of  reptiles  supply  valuable  products  —  alligator  and 

321 


Fig.  154.    Rattlesnake  coiled  to  strike 
After  Ditmars 


Fig.  155.   Copperhead 

After  Ditmars 
322 


REPTILES  323 

snake-skin  leathers,  the  tortoise  shell  of  commerce,  and  the 
flesh  of  some  of  the  marine  turtles  and  fresh-water  terrapins. 
Here  is  a  wide,  almost  new,  field,  and  anyone  who  will  make 
careful  studies  of  habits  and  life  histories,  especially  of  feeding 
tests  with  snakes,  lizards,  or  turtles,  and  even  tests  of  edibility 
in  case  of  likely  forms,  has  a  good  chance  of  advancing  the 
cause  of  valuable  knowledge  and  common  sense. 

Crocodilia.'  The  warm  regions  of  the  world  contain  nineteen  species 
of  big,  burly,  bony-armored  reptiles,  with  long  tails,  powerful  jaws,  and 
tempers  as  ugly  as  their  own  rough  backs.  —  Hornaday. 

To  see  a  live  Alantosaurus  immanis  115  feet  long  —  said  to  be  the 
"  biggest  and  bulkiest  of  all  animals  "  (Gadow)  —  would  make  us  real- 
ize that  our  largest  20-foot  crocodiles  are  mere  pigmy  survivals  of  the 
huge  reptiles  that  ruled  the  world  during  the  Upper  Jurassic.  Accord- 
ing to  Hornaday  only  three  of  the  nineteen  species  are  dangerous  man- 
eaters  —  the  Malayan  salt-water  crocodile  and  two  African  forms.  The. 
two  that  are  natives  of  America,  Crocodilus  acutus  and  Alligator  missis- 
sippiensis,  are  not  man-hunters.  Still,  to  keep  such  hulks  in  food  —  con- 
sisting of  fishes,  waterfowl  and  poultry,  pigs,  and  other  animals  such  as 
they  can  catch  —  is  expensive  and  must  eventually  limit  their  range  to 
zoological  gardens  and  alligator  farms. 

Turtles  —  Chelonia.  Senseless  waste  and  even  cruelty  have  too  often 
characterized  man's  treatment  of  these  defenseless  and  valuable  crea- 
tures. Their  nests  have  been  plundered  for  the  eggs,  whose  value  is 
slight  compared  with  that  of  the  turtles  which  they  might  have  pro- 
duced ;  the  mother  turtles,  when  they  draw  out  of  the  sea  to  lay,  have 
been  turned  on  their  backs  in  numbers  that  could  not  be  utilized,  and 
most  of  them  left  to  struggle  under  the  hot  sun  until  they  died ;  the 
hawksbill,  in  some  countries,  is  hung  over  a  slow  fire  and  roasted  until 
the  precious  shell  plates  loosen  from  the  bone,  when  they  are  stripped 
off  and  the  turtle  is  put  back  into  the  water  under  the  probably  false 
idea  that  it  may  live  to  produce  another  crop  of  shell.  These  are  some 
of  the  abuses  that  ought  to  be  stopped  in  the  name  of  humanity.  While 
it  may  be  a  far  cry  to  ask  savages  of  cannibal  islands  to  treat  sea  turtles 
with  humanity,  we  might,  at  least,  see  that  turtles  of  our  own  coasts  are 
treated  in  humane  and  common-sense  fashion.  They  range  the  tropical 
and  subtropical  oceans  the  world  around,  but  Gadow  says  that  they  prob- 
ably return  to  the  same  beaches  to  lay.    Hence,  if  we  protect  the  turtles 


324 


CIVIC  BIOLOGY 


Fig.  156.    Common  snapping 
turtle 


of  our  own  southern  coasts,  and  especially  their  eggs,  we  may  hope  to  in- 
crease the  American  supply.  May  not  classes  in  biology  work  up  local 
statements  of  this  problem  and  help  to  develop  public  sentiment? 

Of  the  four  species  the  green  turtle 
{Eretmochelys  mydas)  is  most  highly 
prized  for  food.  AVhile  formerly  speci- 
mens weighing  600  pounds  were  cap- 
tured, now  specimens  weighing  more 
than  50  pounds  are  rarely  seen.  The  \og- 
gerhe&d  (Thalassochehjs  caretta)  is  coarser 
and  does  not  command  so  high  a  price, 
but  may  not  be  distinguished  from  prime 
beef  even  by  a  butcher  (Hornaday).  The 
hawksbill  (E.  Imbricatd)  supplies  the  tor- 
toise shell  of  commerce,  but  is  not  used 
for  food.  The  harp  turtle,  or  leather- 
back  (Sphurtjis  coriacea),  the  largest  of  all,  is  said  to  be  unfit  for  food. 
Terrapins  and  tortoises.  The  diamond-backed  terrapin  (Malacoclem- 
mys  palmtris)  is  so  renowned  a  delicacy  with  the  epicures  that  extinction 
of  the  species  has  seemed  imminent.  It  formerly  ranged  from  Massa- 
chusetts to  Mexico  (the  Chesapeake  being  a  center  of  special  abundance), 
inhabiting  the  salt  marshes  and 
feeding  upon  Crustacea,  small  mol- 
lusks,  and  marsh  vegetation.  Prices 
have  risen  from  %^  a  dozen  for  large 
ones  to  $70  for  small  ones,  and  this 
has  so  stimulated  the  hunt  for  them 
that  a  well-grown  sjiecimen  has  be- 
come a  curiosity  in  the  wild  habi- 
tat. Experiments  of  the  United 
States  Bureau  of  Fisheries,  the  re- 
sults of  which  are  given  in  a 
recent  bulletin,  have  proved  that 

this  terrapin  may  be  profitably  reared  in  inclosed  tide  pooh 
tide  flats  are  thus  beginning  to  be  used  for  terrapin  farms. 

The  common  snapping  terrapin,  or  "turtle"  (^Chelydra  serpentina),  and 
the  alligator  terrapin  (Macrochelys  temmincki)  of  the  Gulf  states,  while 
valuable  for  food,  are  "demons  of  the  deep"  (Thompson  Seton)  for 
destroying  waterfowl  and  fishes.  United  effort  should  be  made  to  ex- 
terminate them  from  waters  where  rearing  of  waterfowl  is  an  industry, 


Fig.  157.   Common  box  tortoise 


Waste 


REPTILES 


325 


and  from  the  natural  breeding  grounds  of  wild  ducks  and  geese.  The 
most  effective  means  of  doing  this  would  be  to  find  their  nesting  banks 
and  destroy  the  eggs  or  catch  the  turtles  at  night,  when  they  leave 
the  water  to  lay.  A  female  may  produce  from  2  to  4  dozen  eggs.  The 
soft-shelled  terrapin  {Aspidonectes  ferox)  is  said  to  be  the  best  of  all  the 
fresh-water  forms,  even  the  shell,  properly  cooked,  being  considered  a 
delicacy.  They  are,  however,  vicious  destroyers  of  fishes  and  waterfowl. 

Any  of  the  smaller  mud,  or  pond,  terrapins,  painted  or  spotted,  and 
the  land  tortoises,  offer  interesting  problems  in  the  study  of  foods 
and  possible  edibility.  The  common  box  tortoise  (^Cistudo  Carolina) 
makes  an  interesting  pet,  and  its  appetite  for  slugs  renders  it  a  valu- 
able assistant  to  gardeners.  The  gopher  tortoise  {Testudo  polyphemus) 
of  the  South  may  attain  a 
weight  of  15  pounds.  Tt  is 
considered  edible. 

The  annual  catch  of  food 
turtles,  terrapins,  and  tortoises 
amounts  to  about  1,400,000 
pounds,  valued  at  $114,500. 
What  it  might  be  if  these  re- 
sources were  properly  handled 
has  never  been  estimated. 

Lizards — Lacertilia.  The  Fig.  158.    Common  lizard 

lizards  are  an  effective  in- 
sect police  for  hot,  dry  habitats  not  covered  by  amphibia.  They 
are  difficult  to  keep  in  a  laboratory,  but  if  we  have  a  sunny 
window,  in  which  we  can  imitate  desert  conditions,  we  may 
make  valuable  feeding  tests  with  a  number  of  the  commoner 
forms  —  the  blue-tailed  lizard,  or  skink  (^Uumeces  fasciatus'), 
the  fence  swift  (^Sceloporus  undulatus'),  and  one  of  the  horned 
toads,  or  the  chameleon  (^A^ioUs  carolinensis).  This  may  help 
us  to  realize  the  importance  of  the  group  in  nature.  Lizards 
are  clearly  distinguished  from  all  salamanders  of  somewhat  sim- 
ilar form  by  being  covered  with  scales.  None  of  our  97  species 
of  small,  agile  lizards  are  in  any  way  harmful  or  dangerous. 
The  Gila  monster  (Heloderma  suspectum)  of  the  arid  South- 
west is  the  one  venomous  lizard  native  to  the  United  States. 


326  CIVIC  BIOLOGY 

Snakes  —  Ophidic.  About  140  species  of  snakes  are  native 
to  the  United  States,  of  which  17  are  venomous.  They  are 
all  strictly  carnivorous,  and  the  nonpoisonous  species  are 
beneficial  or  injurious,  according  to  their  foods.  It  is  clear 
that  snakes  which  specialize  on  insects  or  on  rats  and  mice 
should  merit  general  protection.    Our  little  brown  and  green 


Fig.  159.   Aquarium  (24"  x  18'^  x  12")  made  by  student  and  stocked  for  study 

of  native  snakes 
Photograph  by  the  author 

snakes  feed  on  insects,  and  the  corn  snake  (Coluber  guttatus), 
ofteii  called  the  rat  snake,  and  the  gopher  snake  (Spilotes 
corals  eouperii)  are  often  protected  about  the  farmsteads  of 
the  South  for  their  services  in  holding  rodents  in  check. 
The  snakes  that  feed  upon  birds  and  birds'  eggs  (the  black 
snakes  or  the  blue  or  green  racers),  those  that  feed  on  frogs 
and  toads  (the  garter  snakes  and  the  blowing  adder,  or 
spreading  adder),  and  those  that  feed  on  fishes  (the  water 
snakes)  must  be  studied  with  care  and  treated  according  to 
local  conditions  and  interests. 


KEPTILES  327 

Poisonous  snakes.  Fortunately  none  of  our  venomous 
snakes  tend  to  infest  houses,  as  does  the  hooded  cobra  of 
India.  In  consequence,  snake  bites  are  extremely  rare  with 
us,  and  probably  not  more  than  two  deaths  occur  annually 
from  this  cause  (Hornaday).  Of  the  17  venomous  species 
13   are   rattlesnakes,   belonging  to  the   genera    Crotalus  and 


Fig.  160.   Blowing  viper,  trying  to  make  room  for  one  more 
^.  ^  Photograph  by- the  author 

Sistrurus  (the  massasaugas),  so  well  known,  so  clearly  dis- 
tinguished by  the  rattles,  and  so  nearly  extinct  from  all 
settled  regions,  that  they  require  no  description.  It  is  proba- 
bly safe  to  say  that  a  rattlesnake  strikes  only  in  self-defense 
and  that  it  never  gives  chase.  When  coiled  it  cannot  strike 
more  than  one  third  of  its  length,  and  much  less  if  the  neck 
is  drawn  into  an  S-shaped  loop,  and  its  rasping  buzz  gives  a 
warning  that  is  readily  understood  by  both  animals  and  man. 

Closely  related  to  the  rattlesnakes  are  the  two  moccasins  —  the 
upland  moccasin,  or  copperhead  (^Ancistrodon  contortrix),  and  the  ugly 
water  moccasin  (.1.  piscivorus'),  often  called  the  cottonmouth.  The 
copperhead  is  found  among  rocks  and  in  woods  from  Massachusetts 
to  Florida,  ranging  westward  to  Texas  and  northward  to  Indiana.  The 
water  moccasin  inhabits  the  swamps  and  grassy  shores  of  the  bayous 
of  the  Gulf  states,  feeding  largely  on  fish  and  frogs,  and  on  other  snakes. 


328 


CIVIC  BIOLOGY 


The  two  coral  snakes  complete  the  list  of  venomous  species  for  the 
United  States.  These  snakes  do  not  in  the  least  resemble  the  rattlers 
and  moccasins.    Their  heads  are  slender,  not  broad  and  spear-shaped ; 

the  pupil  of  the  eye  is  round 
and  there  is  no  pit  between 
the  eye  and  the  nostril.  They 
look  so  harmless  that,  as  Horn- 
aday  says,  "  it  is  difficult  to  see 
how  anyone  can  be  bitten  by 
this  serpent  without  having  it 
done  by  special  appointment." 
This  is  all  the  more  reason 
for  having  it  definitely  known 
that  these  snakes  are  venom- 
ous. They  belong  to  the  same 
family  (Elapidce)  as  the  deadly 
king  cobra  of  India.  They  are 
instantly  recognized  by  the  brilliant  yellow,  red,  and  black  rings  that 
encircle  the  body  from  the  head  to  the  tip  of  the  tail.  The  two  species' 
are    the    harlequin   snake   (Elaps   fii/rius),  which   ranges   from   South 


Fig.  161. 


Use  of  forked  stick  and  noose 
in  catchins:  a  snake 


Fig.  162.    Coral,  or  harlequin,  snake,  with  yellow  band  around  head  and 
also  between  the  red  and  black  bands  of  the  body 

After  Ditmars 


Carolina  throughout  the  Gulf  states  to  Texas,  and  northward  up  the 
Mississippi  to  southern  Indiana,  —  a  persistent  ground  dweller,  most 
often  seen  when  turned  out  of  the  furrow  by  the  plow,  —  and  the 
Sonoran  coral  snake  (E.  euryxanthus),  confined  to  Arizona,  New  Mexico, 
and  northern  Mexico. 


REPTILES  329 

Snake  venoms  and  the  treatment  of  snake  bites.  Dr.  Calmette,  of  the 
Pasteur  Institute,  succeeded  in  proving  that  snake  venoms  act  upon 
the  body  and  are  reacted  against  by  the  tissues  like  any  other  toxins. 
From  this  it  has  followed  that  antitoxic  sera  may  be  developed  for 
different  snake  poisons,  —  the  antivenins,  —  which  are  able  to  neutralize, 
the  poisons  and  thus  confer  certain  degrees  of  passive  immunity.  When 
this  subject  has  been  thoroughly  worked  out,  we  may  have  specific  and 
sure  remedies  for  all  snake  poisons,  and  this  will  do  away  with  the 
old,  ineffectual  remedies  —  whisky,  sucking  the  wound  (very  dangerous 
unless  the  mouth  is  perfectly  sound),  or  instant  ligature  above  the  bite 
and  quick  excision  of  the  poisoned  tissues.^ 

1  NoGouoHi,  '^  Snake  Venoms,"  Publication  111,  Carnegie  Institution, 
Washington,  1909. 


CHAPTER  XXX 
PRACTICAL  LAWS  OF  LIFE 

Geometrical  Increase  and  Struggle  for  Life.    Vari- 
ation.     Selection    and    Survival    of    the    Fittest. 
Heredity.     Genetics.     Eugenics 

It  is  good  thus  to  try  in  iiiiagiiiation  to  give  to  any  one  species  an  advan- 
tage over  anotlier.  Probably  in  no  single  instance  should  we  know  v^hat 
to  do.  This  ought  to  convince  us  of  our  ignorance  on  the  mutual  relations 
of  all  organic  beings ;  a  conviction  as  necessary  as.  it  is  difficult  to  acquire. 
All  that  we  can  do  is  to  keep  steadily  in  mind  that  each  organic  being 
is  striving  to  increase  in  a  geometrical  ratio ;  that  each  at  some  period 
of  life,  during  some  season  of  the  year,  during  each  generation  or  at  inter- 
vals, has  to  struggle  for  life  and  to  suffer  great  destruction.  When  we 
reflect  on  this  struggle,  we  may  console  ourselves  with  the  full  belief,  that 
the  war  of  nature  is  not  incessant,  that  no  fear  is  felt,  that  death  is  gener- 
ally prompt;  and  that  the  vigorous,  the  healthy,  and  the  happy  survive  and 
multiply.  —  Charles  Darwix,  ''  Origin  of  Species,"  p.  96 

An  exact  determination  of  the  laws  of  heredity  will  probably  work  more 
change  in  man's  outlook  on  the  world  and  in  his  power  over  nature  than 
any  other  advance  in  natural  knowledge  that  can  be  clearly  foreseen. — 
Bateson,  ''Mendel's  Principles  of  Heredity,"  1902,  p.  1 

To  unravel  the  golden  threads  of  inheritance  which  have  bound  us  all 
together  in  the  past,  as  well  as  to  learn  how  to  weave  upon  the  loom  of  the 
future  not  only  those  old  patterns  in  plants  and  animals  and  men  which 
have  already  proven  worth  while,  but  also  to  create  new  organic  designs  of 
an  excellence  hitherto  impossible  or  undreamed  of,  is  the  inspiring  task 
before  the  geneticist  to-day.  —  Walter,  "Genetics,"  p.  5 

It  is  as  impossible  now  to  take  the  ideas  of  descent  and  of  natural  selec- 
tion out  of  the  world  as  to  take  a  star  out  of  the  sky.  —  Cramer,  "  Method 
of  Darwin,"  p.  61 

Mankind  is  slowly  discovering  the  laws  of  life.  Ignorance 
cannot,  in  the  nature  of  the  case,  bring  exemption  from  the 
consequences  of  breaking  laws ;  hence  failure  even  to  try  to 

330 


PRACTICAL  LAWS  OF  LIFE 


331 


learn  the  laws  under  which  we  live  niay  amount  to  criminal 
carelessness.  We  discover  and  learn  laws  in  order  that  we 
may  be  able  to  obey  them,  that  is,  bring  our  lives  into  har- 
mony with  them.  Charles  Darwin,  by  lifelong  application 
and  sacrifice,  marked  the  greatest  advance  in  discovery  of 
the  laws  of  life  that  the  world  has  known.  These  are  not 
far-away  abstractions  of  thought,  and  nothing  can  be  of  more 
intense  practical  value  than  a  knowledge  of  them.  Work 
done  or  life  lived  in  accordance  with  them  is  always  effective 
and  successful,  while  that  done  or 
lived  in  opposition  to  them  is 
always   futile. 

While  it  may  be  sufficient  that 
a  few  specialists  learn  how  to 
control  the  chemical  and  physical 
forces  of  nature  in  accordance  with 
the  laws  of  physics  and  chemistry, 
the  forces  of  living  nature  are  so 
numerous,  affect  the  lives  of  all 
alike  so  intimately,  and  are  so 
powerful  that  common  welfare  re- 
quires of  every  member  of  a  civi- 
lized community  that  he  know  enough  about  them  to  do 
his  part. 

Law  of  geometrical  increase.  All  living  things  tend  to  in- 
crease in  geometrical  ratio.  This  is  the  problem  of  the  farmer 
who  promised  to  pay  the  blacksmith  one  kernel  of  wheat  for 
the  first  *nail  in  his  horse's  hoofs,  two  for  the  second,  four  for 
the  third,  and  so  on.  The  sixty-fourth  nail  alone  would  cost 
him  6,141,451,656,032  bushels  of  wheat  —  more  than  the  en- 
tire wheat  crop  of  the  world  for  2000  years.  The  farmer  did 
not  know  the  law  of  geometrical  increase  when  he  promised 
to  pay  the  wheat.  Millions  of  "  farmers  "  who  do  not  know 
this  law  are  promising  to  pay,  in  control  of  insects  or  fungi 


Fig.  163.  Diagram  showing  five 
generations  doubling   by  geo- 
metrical progression 


332  CIVIC  BlOLOCxY 

and  in  many  other  ways.  Fig.  163  expresses  this  relation  to 
the  eye,  showing  how  quickly  the  world  may  be  covered  or 
any  limit  be  reached,  whether  of  space  or  food  supply,  by  the 
geometrical  increase  of  a  living  species. 

Each  species  has  its  own  formula  or  equation  of  increase, 
its  terms  depending  on  the  number  of  eggs,  seeds,  or  offspring 
and  the  length  of  life  of  a  generation.  Every  species  that 
Ave  need  to  control  or  exterminate,  or  which  we  wish  to  save 
or  increase,  finds  expression  for  its  power  of  good  or  evil  in 
this  law  of  increase.  The  mythical  labors  of  Sisyphus  typify 
humanity  struggling  with  these  problems.  He  w^as  condemned 
to  be  eternally  rolling  a  heavy  stone  up  a  mountain,  the  stone 
slipping  and  rolling  down  again  when  he  had  almost  reached 
the  top.  Flies,  rats,  mosquitoes,  or  some  other  plague,  become 
unendurable,  and  the  community  tries  to  rid  itself  of  them. 
It  rolls  the  stone  almost  to  the  top  of  the  mountain.  A  little 
more  effort,  and  extermination  would  be  complete,  the  stone 
would  be  rolled  over  the  summit  and  disappear;  but  those 
who  do  not  know  this  law  say,  "  Never  mind  these  few, 
they  can't  do  much  harm."  In  a  short  time  the  work  is  all 
to  do  over  again.  So  effective  control  or  conservation  can- 
not be  developed  until  we  have  clear  ideas  of  these  equations 
of  increase. 

Work  out  formulas  of  increase  for  all  sorts  of  types,  good  or  bad,  and 
develop  clearly  their  significance  in  solving  local  problems. 

The  native  American  oyster-shell  scale  produces  one  generation  (about 
50  eggs)  a  year.    Its  equation  of  yearly  increase  is  2  (a  pair)  =  50. 

The  Chinese  (or  San  Jos6)  scale  brings  forth  about  500  living  young 
in  a  period  of  45  days,  having  four  or  five  generations  a  season.  Its 
equation  of  increase  for  a  year  is  2  =  3,216,080,400.  What  bearing  has 
this  upon  thorough  spraying  of  trees  ?  The  native  insect  rarely  injures 
a  tree  perceptibly.  The  imported  scale  threatens  to  exterminate  many 
species  of  trees  from  the  continent. 

The  bobwhite  has  been  known  to  produce  100  eggs  in  a  season. 
Suppose  each  pair  rears  10  young  a  year ;  how  long  would  it  take,  if 


PRACTICAL  LAWS  OF  LIFE  333 

everyone  cooperated,  beginning  with  present  numbers,  or  with  ten  pairs, 
to  increase  them  to  limits  of  insect  and  weed-seed  food  supply  ? 

Figuring  the  number  of  buds  produced  by  a  grape,  peach,  apple, 
strawberry,  or  other  fruit,  the  number  of  eyes  by  a  potato,  the  number 
of  seeds  by  a  grain  or  vegetable  plant,  how  long  would  it  take  to  supply 
every  farm  or  garden  with  a  favorable  variation  ?  This  introduces  us  to 
the  second  practical  law  of  life. 

Law  of  variation.  No  tivo  living  things  are  exactly  alike. 
Can  we  find  two  forest  leaves,  blades  of  grass,  or  human 
faces  exactly  alike?  Living  organisms  are  too  complicated 
for  it  to  happen,  even  by  chance,  that  any  two  should  be 
alike.  So  this  universal  law  of  living  nature  has  given  us  all 
our  different  kinds  of  plants  and  animals. 

Domesticated  plants  and  animals  early  attracted  Darwin's 
attention  as  showing  variations  most  clearly. ^  Horses,  cattle, 
sheep,  dogs,  pigeons,  and  all  manner  of  cultivated  plants  have 
varied  in  the  brief  centuries  of  human  control,  and  are  still 
varying,  in  most  wonderful  fashion.  We  have  horses,  from 
Clydesdales  and  Norman  Percherons  to  Shetland  ponies,  all 
produced  by  human  breeding  and  selection.  Ages  before 
man  appeared  on  the  earth  little  Eohippus,  not  much  larger 
than  a  fox,  with  five  toes,  four  of  them  hoofed,  trotted  over 
the  bogs  of  the  times ;  and  we  can  now  trace  in  successive 
strata  of  rocks  how  the  modern  horse  developed  from  this 
earliest  form.  The  story  of  other  animals  and  even  of  man 
himself  we  have  not  as  yet  been  able  to  trace  so  clearly. 

The  great  practical  values  attaching  to  variations  in  relation 
to  agricultural  productions  are  touched  upon  in  Chapter  IX. 
Since  these  depend  so  largely  upon  the  possibilities  of  increas- 
ing and  propagating  favorable  variations,  we  must  consider 
this  subject  further  in  connection  with  the  greatest  of  all 
biological  laws. 

1  Darwin,  Variations  of  Animals  and  Plants  under  Domestication. 


334  CIVIC  BIOLOGY 

Law  of  heredity.  Organisms  tend  to  produce  offsprifig  like 
themselves.  Variation  is  as  destructive  as  it  is  constructive. 
It  may  give  us  the  Spitzenburg  apple,  and  the  seeds  of  a  Spitz- 
enburg  may  revert  toward  the  original  wild  apple.  Heredity 
is  the  force  that  enables  us  to  conserve  the  gains  supplied  by 
variation.  Organic  reproduction  is  of  two  kinds — asexual,  or 
vegetative,  and  bisexual.  The  asexual  process  is  seen  in 
growth  and  simple  division,  as  found  among  the  bacteria,  or 
growth  with  budding,  as  in  the  yeasts  and  in  plants  generally 
and  in  many  of  the  lower  animals.  In  all  this  reproduction 
we  virtually  have  continuity  of  the  organism,  and  this  can  go 
on  indefinitely  with  little  or  no  variation.  So  buds,  grafts, 
cuttings  (of  stems  or  roots),  layers,  runners,  bulbs,  bulblets, 
tubers,  and,  in  short,  all  purely  vegetative  parts  of  plants 
capable  of  reproduction  carry  the  variety  true  to  name. 
This  means  that  every  bud  on  a  Spitzenburg  apple  tree, 
rooted  in  the  ground  or  grafted  into  any  kind  of  apple 
root  or  branch,  will  produce  a  true  Spitzenburg  tree,  while 
not  a  seed  from  all  the  Spitzenburg  trees  in  the  world  might 
be  able  to  do  this.  There  is  some  talk,  but  little  evidence, 
that  varieties  tend  to  run  out,  or  grow  old,  under  bud 
propagation.  Still  bud  variation  does  occur.  A  branch  of  an 
orange  tree  may  bear  lemons,  or  a  bud  of  a  peach  tree  pro- 
duce nectarines  or  apricots.  Buds  may  also  be  weakened  by 
association  with  disease  organisms  (as  in  diseased  potatoes) 
or,  possibly,  by  lack  of  proper  nutrition,  and  so  give  rise  to 
weakened  stock.  So  we  are  beginning  to  hear  of  pedigree 
selection  of  seed  potatoes  from  healthy,  vigorous,  productive 
hills,  and  of  buds  and  scions  from  healthy  and  fruitful  trees. 
If  these  pomts  are  attended  to,  there  seems  to  be  no  reason 
why  any  variety  may  not  by  bud  propagation  be  held  true  to 
type  indefinitely. 

All  higher  plants  have  adopted  bisexual  reproduction  as 
one   method   of   multiplication   (all   seeds),  and   all    animals 


PRACTICAL  LAWS  OF  LIFE  335 

higher  than  the  worms  and  some  msects  have  come  to  de- 
pend upon  it  entirely.  In  sexual  reproduction  each  indi- 
vidual is  built  up  by  the  mingling  of  the  germinal  elements 
of  two  parents,  and  not  only  that,  but  of  four  grandparents, 
eight  great  grandparents,  and  so  on.  This  mingling,  by  pre- 
potefice  of  some  characters  and  recession  of  others,  causes 
active  variation,  and  this  seems  to  be  the  chief  purpose  of 
bisexual  reproduction.  By  statistical  analysis  Galton  proved 
that  an  individual  receives  on  the  average  50  per  cent  of  his 
characters  from  his 
parents,  25  per  cent 
from  his  grandpar- 
ents, and  the  rest 
from  more  remote  an- 
cestors. Given  all  the 
forces  of  increase,  va- 
riation, and  heredity, 

another  law  comes  into 

,  ,       ,.  „        Fig.  164.    Diagram  illustrating  Mendel's  law 

play,  the  discovery  ot       ^f    dihybrids,    white    being    dominant    and 
which   was    Darwin's  black  recessive 

great  contribution. 

The  law  of  natural  selection.  Nature  selects  the  fittest  to 
survive.  From  the  beginning,  man  has  imitated  nature  in 
selecting  the  plants  and  animals  that  suit  his  need  or  fancy, 
and  this  is  commonly  distinguished  as  artificial  selection. 
Combination  of  these  two  processes  has  resulted  in  the  spe- 
cies and  varieties,  strains  and  breeds,  that  we  now  see  m  the 
world.  Progress  has  been  made  in  the  past  chiefly  by  pick- 
ing up  chance  variations  as  they  have  occurred  in  nature  and 
accidentally  among  domesticated  plants  and  animals.  Only 
within  recent  years  have  we  begun  to  learn  how  to  select 
the  parents  in  order  to  cause  desired  variations.  By  eight 
years  of  most  accurate  and  painstaking  experiments  in  cross- 
ing and  rearing  varieties  of  garden  peas,  the  Austrian  monk. 


336  CIVIC  BIOLOGY 

Gregor  Johann  Mendel,  discovered  a  law  of  heredity,  claimed 
to  be  equal,  for  biology,  to  the  law  of  gravitation  in  physics 
or  to  that  of  atomic  equivalents  in  chemistry. 

MendePs  law.  Characters  are  represented  in  genn  cells  by 
U7uts  which  tend  to  segregate  or  combine  in  definite  propor- 
tions^ the  result  of  mating  together  first  crosses  falling  in  the 
ratios  IDD  -h  2DR  -h  IBR  for  characters   D  a7id  li. 

Illustration.  A  tall  and  a  short  pea  are  crossed.  The  seeds  resulting 
from  the  cross  produce  only  tall  plants.  When  the  seeds  (self-fertilized) 
of  these  plants  are  grown,  they  are  found  to  produce  75  per  cent  tall 
plants  and  25  per  cent  short,  or  3  tall  to  1  short.  Here  tallness  is 
dominant  (character  D)  and  shortness  recessive  (character  R).  A 
dominant  character  dominates  the  outward  form  of  the  plant  or  animal 
body,  while  a  recessive  character  has  its  units  persisting  unchanged  in 
the  germ  cells.  When  male  and  female  germs  again  combine,  they  do 
so  according  to  the  law  of  chance  (like  dice,  or  any  other  free  units) 
and  so  fall  out  IDD  4-  2DR  -f-  IRR.  Since  we  cannot  distinguish  the 
DD  plants  from  the  DR  plants,  except  by  jilanting  the  seeds  and  analyz- 
ing the  i)rogeny,  we  have  3D  to  IR.  All  the  RR  plants  are  found  to  be 
as  pure  and  to  breed  as  true  as  if  they  had  never  been  crossed,  and  so 
are  all  the  DD  plants  when  we  propagate  them.  The  DR  plants  will 
continue  forever  to  produce  IDD  -I-  2DR  -f  IRR.  A  hybrid  can  never 
1)6  fixed  so  as  to  breed  true. 

The  above  is  the  law  for  monohybrids  —  tt)rms  in  which  a  single 
character  or  pair  of  characters  is  involved,  and  instead  of  assuming 
the  presence  of  a  unit  (determiner)  for  a  character  (for  example, 
shortness),  the  tendency  is  to  assume  merely  the  absence  of  the  germi- 
nal determiner  for  tallness.  In  cases  of  two  characters  being  involved 
in  each  parent,  that  is,  in  dihybrids  (characters  Dd  and  Rr),  there  is 
IDd-Dd  and  IRr-Rr,  that  is,  1  pure  dominant  and  1  pure  recessive  in 
16.  In  case  of  trihybrids  only  1  offspring  in  64  is  pure  dominant  or 
l)ure  recessive.  If  ten  characters  are  involved,  the  offspring  of  the  sec- 
ond generation  would  fall  into  1,048,576  different  kinds,  of  which  only 
1  would  be  pure  for  each  set  of  characters. 

When  we  consider  that  this  law  of  inheritance  applies-  to  fixation  of 
all  kinds  of  characters,  from  tallness  of  peas  to  tallness  of  men,  from 
rust  resistance  in  wheat,  egg  production  in  poultry,  or  milk  production 
of  cows  to  feeble-mind edness  or  normal  intelligence  in  men,  we  begin 


PKACTKJAL  LAWS  OF  LIFE 


337 


to  realize  what  Mendel  has  done  for  the  world.  As  Walter  sums  up  th«* 
case :  "  Thus  in  a  few  generations  of  properly  directed  crosses  there 
can  be  obtained  combinations  of  cluiracters  united  in  one  strain  that 
formerly  w^ere  never  obtained  at  all  or  were  only  hit  upon  by  merest 
chance  at  long  intervals.  Herein  lies  the  scientific  control  of  heredity 
which  the  trinity  of  Mendelian  principles,  namely,  independent  imit 
characters,  segregation,  and  dominance,  has  placed  in  human  liands."  ^ 

Historical.  Mendel  presented  the  re- 
sults of  his  era-making  experiments 
before  the  Natural  History  Society  in 
Briinn  early  in  1865,  and  they  were 
published  in  the  Proceedings  in  1866. 
Neither  the  reading  nor  the  publication 
caused  a  ripple  of  interest.  No  one  un- 
derstood its  significance.  Had  Darwin 
learned  of  Mendel's  law  in  1865,  the 
liistory  of  human  science,  philosophy, 
and  even  religion  might  have  been 
pushed  forward  fifty  years.  Mendel  died 
January  6,  1884,  bitterly  disappointed 
that  no  one  could  be  found  to  share  his 
vision,  and  his  discovery  slumbered  for 
sixteen  years  longer. 

In  1900,  three  men,  working  independ- 
ently, rediscovered  Mendel's  law  almost 
at  the  same  time.  These  were  De  Vries 
in   Holland,   Correns  in  Germany,  and 

Tschermak  in  Austria.  The  time  was  ripe  for  its  appreciation,  and  it 
immediately  transformed  the  subject  and,  from  a  matter  of  abstract 
disquisitions,  made  heredity  the  most  intensely  practical  concern  of  the 
experimental  breeding  plot  and  pen,  of  the  hunt  for  variations  in  nature, 
and  of  even  sociological  analyses  and  surveys.  "  The  practical  breeder 
of  animals  or  plants,  basing  his  methods  on  a  determination  of  the 
Mendelian  units  and  their  properties,  will  in  many  of  his  operations 
be  able  to  proceed  with  confidence  and  rapidity.  Lastly,  those  who  as 
evolutionists  or  sociologists  are  striving  for  wider  views  of  the  past  or 
of  the  future  of  living  things  may  by  the  use  of  Mendelian  analysis 
attain  to  a  new  and  as  yet  limitless  horizon."  ^ 


Fig.  166.  Diagram  illustrating 

relation  of  germ  plasm  (straight 

lines)  to  somatoplasm  (circles) 

in  bisexual  reproduction 


1  Walter,  Genetics,  p.  144. 

2  Bateson,  Mendel's  Principles  of  Heredity,  1909,  p.  17. 


388  CIVIC  BIOLOGY 

Evolution,  mutation,  and  Mendel's  law.  Tn  his  scheme  of  evolution 
Darwin  emphasized  the  influence  of  slight  variations  continued  through 
long  periods  of  time.  He.  realized  at  the  outset  that  in  heredity,  in  the 
power  to  pass  on  variations,  lay  the  heart  of  his  problem,  but  he  went 
far  astray  in  his  own  theory  of  heredity,  pangenesis,^  and  so  failed  to 
attain  the  goal  he  might  have  won.  No  one  realized  this  more  keenly 
than  Darwin  himself. 

De  Vries  found  that  from  the  same  seed  capsule  of  Lamarck's  eve- 
ning primrose  he  could  rear  as  many  as  nine  distinct  kinds  of  plants,  so 
different  that,  had  they  occurred  consistently  in  nature,  they  might 
have  been  named  as  separate  species.  On  the  basis  of  these  and  similar 
experiments  he  advanced  his  recent  theory  of  mutation.  This  theory 
supposed  that  evolution  goes  forward  by  leaps  and  sudden  changes.  It 
now  turns  out  that  this  evening  primrose,  Gi,nnthera  lamarckiana,  is 
a  Mendelian  cross,  a  hybrid ;  and  this  suggests  that  all  mutations  may 
be  merely  cases  of  segregation  and  recombination  of  unit  characters  in 
the  germs  of  plants  and  animals,  that  is,  outworkings  of  Mendel's  laM^ 

Weismann  made  a  solid  contribution  when  he  distinguished  sharply 
between  germ  plasm  and  body  plasm,  or  somatoplasm.  He  called  atten- 
tion to  the  fact  that  the  germs  are  all  formed  in  the  embryo  long 
before  the  body;  the  egg-germs,  and  many  more  than  a  hen  can  ever 
hope  to  lay,  are  all  set  aside  at  almost  the  very  beginning  of  incubation. 

1  Pangenesis  (pan,  "all,"  or  '^  the  whole,"  and  genesis^  ''  origin  "  —  that 
is,  ''from  the  whole  body")  is  the  theory  that  the  germ  cells  are  built  up 
by  the  streaming  together,  from  all  the  organs  of  the  body,  of  minute  parti- 
cles (gemmules,  or  pangens)  —  an  infolding  or  involution  of  the  body  into 
the  germ.  Then  when  a  germ  unfolds  or  develops,  each  pangen  reproduces 
the  part  of  the  body  from  which  it  came.  This  theory  implies  an  active 
influence  of  the  body  upon  the  germ  plasm,  and  if  parts  of  the  body  or  brain 
should  be  specially  developed  by  exercise  or  training,  or  if  partfe  or  organs 
should  be  removed  or  lost  by  disease  or  accident,  we  should  expect  to  find 
such  additions  or  subtractions  reproduced  when  the  germs  from  such  bodies 
developed.  This  we  never  find.  There  is  no  evidence  that  any  acquired 
character  is  ever  inherited.  Lambs'  tails  have  been  bobbed  for  thousands 
of  years,  and  lambs  are  born  with  tails  as  long  as  they  ever  were.  Galton 
disproved  pangenesis  experimentally  by  exchanging  the  blood  of  animals. 
Since  the  blood  is  the  only  means  by  which  the  pangens  could  possibly 
circulate  from  the  body  to  the  reproductive  cells,  if  we  exchange  blood 
between  white  and  Jblack  animals,  we  ought  to  get  some  of  the  pangens 
mixed.  Galton's  experiments  disproved  the  theory  absolutely,  as  does  every 
case  of  budding  and  grafting. 


PKACTICAL  LAWS  OF  LIFE  339 

Germ  plasm  forms  genu  plasm  and  builds  up  tlie  body,  but  the  body 
cannot  form  or  reproduce  a  single  pangen  or  minutest  particle  of 
germ  plasm. 

Organized  study  of  genetics.  What  is  your  own  community 
doing  to  improve  its  plants  and  animals?  Many  investi- 
gators  and   students   in   our   universities   and   colleges,   our 


^  T  looked  about  to  iee  nhat  1  comdfma 

amons  our  Hildin^S.  The  next  tiling  to  do  waS  to  fund 
tKe  tesl  and  earlis5t  grape  for  Seed  and  tnis  1  lound  in    | 
an  accidental  seedling  at  iKe  foot  of  the  luill .  The  crop      j 
Mas  atundant  ripe  in  Augugl  and  of  very  good  c|ual!ty  | 
for  a  n'Jd  grape.  1  ^owed  \\\e  Seed  in  the  autunm  of 
1843.  Among  them  the  Concord  Mas  ^^^  only  j 

one  Horlhsavini?. 


Fig.  166.    Quotation  from  Mr.  Ephraim  Bull  on  the  wooden  tablet  marking 
the  original  Concord  grapevine  at  Concord,  Massachusetts 

Agricultural  Department  and  experiment  stations,  practical 
seedsmen,  farmers,  and  independent  plant  and  animal  breed- 
ers, are  studying  and  experimenting  and  pushing  discovery  in 
this  field.  Invite  local  experts  to  visit  the  class  and  discuss 
their  problems.  Often  by  community  cooperation  better  stock 
can  be  introduced  than  iany  one  member  could  afford,  and  its 
rapid  increase  insures  enormous  profits  to  such  undertakings. 
Railroad  companies  and  the  International  Harvester  Company 
have  agricultural  experts  who  are  helping  along  these  lines. 
Hunt  out  stories  of  the  discovery  and  introduction  of  new 
fruits,  vegetables,  grains,  breeds  of  animals,  and  in  the  spirit 


340 


CIVIC  BIOLOGY 


of  these  try  to  fiiid  valuable  variations  in  the  neighborhood. 
Our  native  iiut  trees  have  been  neglected  in  this  matter,  and 
the  Department  of  Agriculture  is  calling  for  a  special  search 
of  the  entire  continent  for  valuable  varieties.  With  the  whole 
country  organized  for  the  search  and  with  breeding  in  control 
of  experts,  we  may  hope  for  better  progress  in  every  line  of 
plant  and  animal  improvement  than  ever  was  known  before. 
Injury  of  germ  plasm.  Germinal  substance  is,  of  course, 
obliged  to  draw  its  nourishment  from  the  body;  hence  we 
may  expect  to  find  vigorous  germs  m  strong,  healthy  bodies. 
Animals  that  become  too  fat  are  likely  to  have  enfeebled 
germs  or  to  be  totally  sterile,  and  conditions  that  show  no 
appreciable  injury  to  the  body  may  prove  fatal  to  the  germ 
plasm.  This  is  seen  in  Stockard's  experiments  with  alcohol 
tabulated  below: 


Experiments  with  (U  inea  Tigs  to  test  Influence  ok  Alcohol 
ON  Germ  Cells 


Alcoholic 

Alcoholic  males  and  normal  females 
Normal  males  and  alcoholic  females 
Alcoholic  males  and  alcoholic  females 

Control 
Normal  males  and  normal  females 


Num- 
ber OF 
Mat- 
ing s 


Abor- 
tive 


Died 

AT 

Birth 


Live 


7         5  (all  runts) 
2      !  2 
1      i  0 


7  (all  vigorous) 


The  germ  cell  from  each  parent  builds  half  the  embryo,  and 
the  twenty-four  matings  in  which  the  sperm  alone  is  alcohol- 
ized are  a  proof  that  an  alcoholized  sperm  cell  of  a  guinea 
pig  cannot  do  its  share  toward  building  up  a  normal  offspring.^ 

1  Stockard  allowed  the  guinea  pigs  to  breathe  fumes  of  alcohol  for  one 
hour  a  day,  six  days  in  the  week.  The  animals  showed  no  outward  injury, 
in  fact  they  gained  somewhat  in  weight. 


PRACTICAL  LAWS  OF  LIFE 


341 


The  following  table  shows  similar  results  obtained  by 
Hodge  from  carefully  balanced  experiments  with  selected 
dogs.  The  males  were  brothers  and  the  females  sisters  from 
two  unrelated  litters  of  pedigree  cocker  spaniels.  Demme's 
observations  upon  men  are  added  for  comparison. 

Infj.i'knoe  of  Alcohol  on  Pko<jkny 
Dogs  (Hodge) 


Number  of  whelps 
Deformed  ... 
Born  dead  .    .    .    . 
Viable 


Alcoholic  Pair 


(7-7-6-3)  23 

(2-3-3-0)  8 

(2-2-2-3)  .9 

(4-0-0-0)  4  (!' 


■4%) 


Normal  Pair 


(5-3-8-8-5-6-3-7)  45 
(1-0-0-2-0-0-0-1)  4 
(0-0-0-0-0-0-0-0)  0 
(4-3-8-6-5-6-3-6)  41  (90.2  %) 


Men  (Demme) 


Ten  Alcoholic 
Families 

Ten  Normal 
Families 

Number  of  children 

Deformed 

Idiotic 

Epileptic,  choreic 

Died  at  birth 

Normal,  viable 

57 
10 

6 

6 
25 
10  (17%) 

61 
2 
0 
0  (2bkw) 

54(88.5%) 

Moderate,  nonintoxicating  doses  of  chemically  pure  alco- 
hol were  fed  to  the  dogs  with  their  meals,  and  Demme's 
normal  families  were  not  total  abstainers.  In  further  study 
of  the  human  problem  Bezzola  found  that  out  of  8190  idiots 
in  Switzerland  the  majority  occurred  in  the  wine  districts, 
and  that  the  larger  per  cent  of  these  were  born  nine  months 
after  the  great  national  drinking  feasts.  Schweighofer  dis- 
covered a  similar  relation  between  stillbirths  and  the  drink- 
ing festivals  of  Austria. 

To  keep  the  germ  plasm  of  the  nation  on  the  up-grade, 
free  from  any  injury,  taint,  or  tendency  to  degeneration,  is 
the   most  worthy  subject  for  lifelong   study  by  every  man 


Caspar 

0- 


<N) 


<n) 


<n) 


The  Uwful  Wife  I     The  Nameless  Feeble-Minded  Girl 

Not  Marrieiii 


(N> 


(N> 


(n>- 


®- 


0- 


Martin 

Kallikak,'8r. 

d.  1837 


Frederick  Martin 

Kallikak,  Jr 


<n) 


Millard 


Justin 


^ 


® 


Fig.  167.    Diagram  outlining  history  of  Kallikak  family- 
Squares  stand  for  males,  circles  for  females ;   N  for  normal  people,  F  for  feeble- 
minded.  Five  generations  on  the  side  of  the  feeble-minded  girl  contain  480  indi- 
viduals— 143  feeble-minded,  33  immoral,  24  drunkards,  and  3  epileptics.   On  the 
normal  side  are  496  descendants,  none  of  whom  are  feeble-minded.  After  Goddard 


342 


PRACTICAL  LAWS  OF  LIFE  343 

and  woman.  We  ai'e  now  just  beginning  to  learn  facts  in 
this  field  which  may  save  our  present  civilization  from  the 
decays  that  have  overtaken  those  of  the  past.  Whatever  a 
man  may  claim  for  personal  liberty,  no  one  can  claim  any 
right  to  even  risk  mental  or  physical  impairment  of  his 
own  offspring  or  to  impose  the  care  of  defectives  upon  the 
community.  Alcohol  is  being  barred  from  athletics,  from 
the  army  and  navy,  from  public  service,  and  from  all  busi- 
ness, public  and  private,  where  strength,  endurance,  and 
dependability   are   required,  and   the   evidence   given   above 


2  j  Neurotic  d. 

[n]  6  (n)  [n]  [j  (n) 


liM^iiM^Ki^ 


2  4  3N         2M 


I      I      I      I      t      I      I 


Fig.  168.  Recessive  character  of  feeble-mindedness  and  effects  of  alcoholism 

Small  black  circles  indicate  stillbirths ;  d,  died  ;  d.  inf.,  died  in  infancy :  t,  tuber- 
cular; u,  unknown.   For  other  symbols  see  Fig.  167.   After  Goddard 

would  seem  not  only  to  give  society  the  right  but  to  impose 
upon  it  the  duty  of  banishing  alcohol  from  any  possible 
contact  with  the  supreme  business  of  evolving  the  race. 
"  You  can't  be  strong  and  well  unless  you  live  right'" 
These  words  of  Jess  Willard  are  life-wide  in  their  applica- 
tion. We  are  just  beginning  to  learn  from  the  new  view- 
point of  eugenics.  Drugs  like  morphine  and  opium,  cocaine 
and  heroin,  must  be  studied  with  special  reference  to  their  in- 
fluence upon  the  germ  plasm.  The  same  is  true  of  nicotine, 
and  it  may  be  that  we  shall  have  to  set  the  age  at  which 
indulgence  in  tobacco  may  safely  be  begun  at  fifty-five 
years  instead  of  at  the  usual  sixteen  or  twenty-one.     Any 


344  CIVIC  BIOLOGY 

excess  in  the  use  of  coffee  or  tea  must  be  viewed  with 
suspicion,  and  many  of  our  best  hygienists  look  with  appre- 
hension at  the  possible  consequences  to  the  race  of  our 
sudden,  enormously  increased  gorging  of  sugar.  We  can 
only  suggest  these  as  possible  lines  of  study. 

Eugenics  and  MendePs  law ;  bad  blood  and  good.  ''  Peo- 
ple say  one  must  be  able  to  read  and  write  in  order  to  get 

along  in  the  world.     Now  there  is  Miss .    She  cannot 

read  or  write,  yet  she  gets  along  all  right."  ^ 

This  judgment  of  a  feeble-minded  woman  by  an  imbecile  man 
helps  to  explain  the  rapid  increase  of  such  defectives.  Avoided 
by  the  normal,  defectives  generally  marry  defectives.  Since 
they  are  permitted  to  multiply  at  will  and  are  shielded  by 
modern  charity  from  operation  of  the  law  of  survival  of  the  fit, 
this  process  has  gone  on  until  we  now  have  nearly  3,000,000 
dependents  and  defectives  —  one  in  thirty  of  our  population.^ 
By  far  the  larger  part  (quite  possibly,  when  we  have  studied 
to  the  real  genetic  root  of  the  matter,  we  shall  find  that  al- 
most all)  of  the  heavy  burdens  imposed  upon  society  by  the 
idiotic,  imbecile,  and  insane,  the  paupers,  alcoholics,  and 
criminals,  is  caused  by  inherited  mental  and  moral  defect. 

The  exhaustive  studies  of  Goddard  seem  to  leave  no  room 
for  doubt  that  feeble-mindedness  is  a  recessive,  Mendelian, 
unit  character.  Hence,  according  to  Mendel's  law,  the  chil- 
dren of  feeble-minded  parents  must  forever  all  be  feeble- 
minded. Goddard  finds  this  to  be  true.  Normal-mindedness 
is  a  dominant  unit  character.  Hence,  if  one  parent  is  pure 
normal  (duplex)  and  the  other  feeble-minded  (nulliplex),  the 
children  will  appear  normal  but  will  all  have  feeble-mindedness 
recessive  (that  is,  be  simplex).  When  such  people  become 
parents,  the  children  will  be  IDD  -f  2DR  +  IRR,  that  is, 
three  normal  to  outward  appearance  and  one  feeble-minded. 

1  Goddard,  Feeble-mindedness  :  its  Causes  and  Consequences,  p.  85. 

2  Kellicott,  Social  Direction  of  Human  Evolution,  p.  34. 


PRACTICAL  LAWS  OF  LIFE  345 

Since  these  people  are  a  burden  to  themselves  and  to 
society,  no  right-minded  person  could  risk  the  responsibility 
for  bringing  them  into  the  world ;  and  as  the  facts  come  to 
be  generally  known,  all  such  streams  of  bad  blood  will  be 
prevented  from  increasing  then*  kind  and  also  from  spread- 
ing out  to  contaminate  streams  of  normal  blood. 

Color  of  eyes  and  hair,  night  blindness,  color  blindness, 
albinism,  germinal  deaf-mutism,  and  many  other  human 
characters  have  been  found  to  follow  Mendel's  law,  but  dis- 
covery is  only  beginning  to  break  into  this  field,  and  we 
merely  suggest  it  for  future  individual  study.  Most  impor- 
tant studies  have  been  made  on  typical  streams  of  bad 
heredity.  Let  different  members  of  the  class  volunteer  to 
look  up  the  following  and  report :  "  The  Jukes  Family,"  by 
Dugdale  ;  "  The  Zero  Family,"  by  Jorger ;  ''  The  Hill  Folk," 
by  Danielson  and  Davenport ;  "  The  Nam  Family,"  by 
Estabrook  and  Davenport ;  and  ''  The  Kallikak  Family," 
by  Goddard. 


CHAPTER  XXXI 
KNOWING  HOW  TO  KNOW  HOW 

National  Organization  for  Biological  Instruction 
AND  Research 

I  do  not  know  what  I  may  appear  to  the  world ;  but  to  myself  I  seem  to 
have  been  only  like  a  boy  playing  on  the  seashore,  and  diverting  myself  in 
now  and  then  finding  a  smoother  pebble  or  a  prettier  shell  than  ordinary, 
whilst  the  great  ocean  of  truth  lay  all  undiscovered  before  me.  —  Sir  Isaac 
Newtox 

It's  easy  enough  to  do  it  if  you  only  know  how.  It's  easy  enough  to 
do  everything,  if  you  —  if  you  only  know  how.  —  Small  Boy  (overheard 
on  the  street) 

Conclusion  of  the  whole  matter.  The  best  ''  knowmg  how  " 
there  is  in  the  world  is  none  too  good  for  the  humblest  child 
of  the  nation  to  try  to  live  and  to  work  by.  If  there  were 
one  wish  that  the  writers  of  this  book  could  have  granted 
for  the  askmg,  it  would  not  be  that  everybody  should  know 
everything,  but  that  every  child  of  the  nation  should  know 
how  to  learn  only  the  best  truth  there  is  to  help  him  with 
each  day's  life  and  work.  The  doing  may  be  easy  and  cheap ; 
the  knowing  how  is  very  precious  and  may  have  cost  years 
or  centuries  of  trying,  thinking,  and  experimentmg.  Still  the 
knowing  how  may  be  easy,  too,  if  we  really  know  how  to 
know  how.  Is  it  not  being  continually  baffled  by  false, 
wrong,  bad  knowing  how  that  makes  all  learning  hard  and 
work  futile  ?  It  is  easy  to  keep  well  and  strong  if  we  know 
how,  but  the  knowing  how  must  be- right.  It  would  be  easy 
to  exterminate  tubercle  bacilli  if  everybody  knew  how,  but 
we  cannot  do  this  as  long  as  even  a  few  think  they  know 

346 


KNOWING  HOW  TO  KNOW  HOW  347 

how  to  do  it  with  Dr.  Muck's  compound  of  punk,  alias 
cheap  whisky.  It  would  be  easy  to  breed  and  raise  100- 
bushel  wheat,  200-bushel  corn,  1000-bushel  potatoes,  1000- 
pound-butter-fat  cows,  300-egg  hens,  and  so  on  down  the  list, 
if  we  only  knew  how.  We  are  gaining  ground  yearly ;  the 
doing  is  step  by  step  a  test  of  the  knowing. 

Fake  sources  of  truth  like  poisoned  wells.  Sometime  we 
may  be  organized  as  a  people,  so  that  only  the  truth  can  be 
printed.  Our  pure  food  and  drug  laws  are  beginnings  in  this 
direction,  but  the  millennium  is  still  a  long  way  off,  and  so 
far  attempts  at  assumption  of  human  infallibility  have  been 
failures.  All  we  can  do  is  to  appeal  for  information  to  our 
best  authorities.  These  pretend  to  no  secrets  for  a  price ; 
they  always  present  the  evidence,  the  proofs,  the  experi- 
ments, on  which  their  conclusions  are  based ;  and  it  ought  to 
be  possible  to  add,  they  never  say  they  know  a  thing  when 
they  do  not ;  that  is,  they  never  lie.  No  one  can  long  remain 
an  authority  if  often  mistaken  on  this  most  important  of  all 
points,  and  a  real  authority  is  never  afraid  to  say,  "I  do  not 
know."  Successful  farmers  in  different  Imes,  our  county 
agricultural  expert,  Igcal  nurseryman  and  florist,  local  forester 
or  tree  warden,  local  bird  man  or  woman  (unfortunately  we 
seldom  have  any  local  insect  students),  local  health  officers 
and  reputable  physicians,  state  and  national  experiment- 
station  experts  and  health  officers,  and  the  extension  faculties 
of  our  state  universities  —  these  are  our  best  authorities. 
They  belong  to  us ;  we  pay  some  of  them  their  salaries  to 
give  us  the  best  knowing  how  there  is ;  and  they  are  gladder 
to  do  it  than  we  are  to  wake  up  enough  to  ask  them*  for 
help.  By  the  divine  right  of  being  alive  the  best  knowing^ 
how  there  is  in  the  world  belongs  to  any  child  of  humanity 
who  is  hungry  for  it  and  who  knows  enough  to  ask  for  it 
and  to  learn  it.  Our  country  is  organized,  through  its  edu- 
cational forces,  public  press,  and  public  libraries,  to  meet  this 


348  CIVIC  lUOLOOY 

right,  as  any  child  of  the  nation  can  test  as  often  as  he  pleases. 
The  great  lack  is  that  we  are  not  educated  to  know  and  to 
utilize  the  resources  for  knowing  how  that  belong  to  us. 
Another  great  difficulty  is  that  the  world  is  flooded  with 
fake,  false,  selfish-motived  misinformation,  and  Ave  need  to 
learn  to  shun  all  bad  and  second-rate  sources  of  truth  as  we 
would  poisoned  wells.  In  proportion  as  one  uses  the  best 
sources  of  information,  he  will  develop  the  power  to  discrimi- 
nate and  to  detect  the  bad.  Civic  biology  should,  first  of  all, 
save  us  from  fake  solutions  of  our  health  problems. 

No,  Mrs.  Bonebrake,  I  am  not  going  to  try  your  religious  fad  in 
order  to  heal  my  sore  feet ;  no,  IVIrs.  Hardscrabble,  T  will  not  use  your 
number  rigmarole  to  improve  my  prospects ;  and  no,  IVIrs.  Likenbower, 
I  will  not  wear  your  amulet  to  get  rid  of  my  rheumatism. 

Why?  Well,  because  I  am  honest.  I  may  not  be  very  holy  or  soul- 
emancipated,  but  I  pride  myself  on  being  an  honest  man. 

And  I'm  going  to  be  as  honest  with  myself  as  T  am  with  my  neighbor. 

The  fundamental  ethics  is  the  ethics  of  the  intellect. 

And  that  means  that  I  will  believe  only  upon  examining  the  facts. 
My  judgment  shall  remain  absolutely  automatic,  and  shall  bend  only 
by  weight  of  evidence. 

I  shall  not  say  I  believe  a  thing  just  to  see  if  it  will  not  help  me. 

I  shall  refuse  to  proclaim  a  faith  in  order  to  help  anybody  else. 

Ladies,  you  touch  the  quick  of  my  virtue.  T  will  not  be  disloyal  to 
my  reason  —  no,  not  even  to  get  to  heaven. 

History  is  full  of  pious  and  learned  men  who  put  expediency  before 
honesty.  They  did  not  believe  what  they  professed  —  they  did  not  even 
understand  it ;  but  they  said  they  did,  because  they  thought  it  would 
aid  others,  would  not  offend  the  weak,  and  would  save  their  own 
souls. 

But  I  will  take  my  chances  with  intellectual  integrity  alongside  of 
all  the  earnest  souls  who  deceived  themselves  and  everybody  else  be- 
cause, so  doing,  they  verily  thought  they  were  doing  the  will  of  heaven. 

I  know,  Mrs.  Bonebrake,  you  claim  that  your  peculiar  faith,  resting 
upon  a  plain  denial  of  facts,  has  healed  many ;  so,  Mrs.  Hardscrabble, 
your  cabala ;  and  so,  Mrs.  Likenbower,  your  amulet.  Why  not  try  it  ? 
It  has  benefited  others ;  why  not  me  ? 


KNOWING  HOW  TO  KNOW  HOW  349 

Simply  because  every  one  of  your  cures  can  be  traced  as  justly  to  the 
strange,  mysterious,  recuperative  powers  of  nature  as  to  your  particular 
nostrum  or  form  of  self-hypnotism. 

Thousands  of  invalids  have  got  well  after  being  given  up  by  phy- 
sicians, and  got  well  without  crossing  their  fingers  and  reading  your 
book.  In  fact,  most  people,  some  time  in  their  life,  have  miraculously 
recovered  when  it  seemed  they  should  have  died. 

Hence,  if  you  bottle  Chicago  river  water  and  get  enough  people  to 
"  just  try  "  it,  you  can  collect  innumerable  testimonials.  But  doubtless 
if  you  published  these  you  would  not  include  in  your  report  the  equally 
innumerable  cases  where  the  victim  did  not  get  well. 

No,  ladies;  I  appreciate  your  kindly  interest  in  my  bodily  health 
and  my  soul's  salvation,  but  I'm  going  to  stay  honest  and  see  what 
happens. 

>  When  I  am  met  by  a  proposition  that  is  based  on  facts,  and  not  on 
the  ignoring  of  them,  that  is  reasonable  and  convincing,  and  that  is 
substantiated  by  the  known  laws  of  evidence  and  squares  with  common 
sense,  I  will  embrace  it.    Otherwise,  no ;  and  thank  you  all  the  same. 

Nothing  doing  on  the  esoteric,  the  fuzz-wuzzy,  the  ecstatic,  the  self- 
hypnotic,  the  what-if-it-is-true-after-all-you-can't-tell. 

My  intelligence  may  be  pretty  poor,  but  it 's  all  I  have.  I'm  going 
to  stand  by  it  and  refuse  to  prostitute  it,  no  matter  what  the  bribe. 

The  web  of  destiny  is  complex,  I  know,  and  none  of  us  knows  the 
secret  springs  of  life  and  events;  but  I  have  a  notion  that  if  a  man 
sticks  to  the  truth  as  he  sees  it,  and  declines  the  lure  of  truth  as  he  does 
not  see  it,  even  if  the  latter  promises  health,  wealth,  and  a  happy  here- 
after, he  will  be  likely  to  come  out  about  where  his  Creator  intended. ^ 

Using  a  library.  The  best  investment  any  connnunity  can 
make  is  to  buy,  catalogue,  and  keep  up  to  date  a  library 
relating  to  its  interests  and  industries ;  and,  in  any  modern 
sense  of  the  word,  that  one  is  most  efficiently  educated  who 
best  knows  how  to  use  such  a  library.  If  our  local  and  school 
libraries  are  properly  managed  and  catalogued,  it  ought  to 
be  easy  to  find  quickly  all  that  is  known  on  every  subject 
discussed  in  this  book.  If  every  member  of  the  class  is  col- 
lecting bulletins  up  to   date   and  doing  his  share  to   help, 

1  By  Dr.  Frank  Crane,  in  the  As.sociated  Newspapers, 


350  CIVIC  BIOLOGY 

the  laboratory  bookshelf  ought  to  be  made  to  answer  95  per 
cent  of  the  questions  that  arise.  Individual  pupils  should 
also  be  gathering  libraries  relating  to  their  own  problems, 
interests,  and  projects.  A  really  practical  working  method 
in  using  a  library  is  of  lifelong  value  to  everyone.  How 
many  have  acquired  this  at  the  end  of  their  school  or  even 
college  courses  ?  This  is  the  one  thing  necessary  to  reason- 
ably intelligent  modern  living,  and  if  many  have  failed  to 
acquire  .it  in  the  course  of  their  schooling,  is  it  not  because 
they  have  not  had  any  real  problems  to  solve  that  required 
such  use  of  libraries  ?  Lincoln  stated  the  case  in  a  word 
when  he  said :  ''A  capacity  and  taste  for  reading  gives  access 
to  whatever  has  already  been  discovered  by  others.  It  is  the 
key,  or  one  of  the  keys,  to  the  already  solved  problems. 
And  not  only  so:  it  gives  a  relish  and  facility  for  success- 
fully pursuing  the  unsolved  ones  "  (p.  92). 

Catalogues,  publication  lists,  and  indexes.  A  library  may  be 
too  poor  to  buy  many  books,  but  still  be  100  per  cent  efficient 
if  it  keeps  these  indispensable  helps  in  order  and  up  to  date. 
People  can  then  find  everything  that  has  been  written  on  any 
subject  or  by  any  author,  and  the  local  library  can  usually 
borrow  from  the  state  library  or  from  that  of  their  nearest 
university;  or  people  might  often  buy  books  and  donate  them 
to  their  local  library  when  they  have  finished  with  them. 

Every  laboratory  bookshelf  must  have  for  constant  refer- 
ence the  Monthly  Lid  of  Publications  (which  is  sent  free  to 
all  who  apply  for  it)  and  the  Experiment  Station  Record  J 
The  first  lists  every  bulletin  of  the  central  Department  at 
Washington,  as  it  appears,  and  the  Experiment  Station  Record 
gives  a  well-annotated  monthly  bibliography  of  everything 
relating  to  the  practical  biology  of  agricultural  advancement 
for  the  entire  country  and,  in  fact,  for  the  world.    Another 

1  For  both  these  publications  address  United  States  Department  of  Agri- 
culture, Washington,  D.C.    Subscription  price  of  the  Record  is  $1  a  year. 


KNOWING  HOW  TO  KNOW  HOW  351 

publication  of  the  Department  is  the  Weekly  News  Letter^ 
which  contains  brief,  timely  articles  and  notes.  Some  mem- 
ber of  the  class  might  subscribe  for  this  and  keep  it  in 
orderly  file  on  the  bookshelf. 

The  question  with  which  we  started  is,  How  can  we  get 
the  best  information  most  quickly?  A  concrete  case  will 
answer  this  question  for  thousands  of  similar  problems. 

A  botany  class  in  a  city  was  beginning  the  study  of  fungi,  and  in 
addition  to  the  elementary  book  work  each  member  was  assigned  an 
interesting  fungus  to  work  up  and  report  upon.  One  of  the  boys,  instead 
of  the  fungus  assigned  him,  asked  permission  to  take  the  black  knot. 
The  teacher  was  wise  and  honest  enough  to  tell  him  that  she  knew 
nothing  about  it,  but  would  be  glad  if  he  would  learn  all  he  could  and 
give  them  all  the  benefit.  He  went  to  the  library  with  a  pack  of  postal 
cards  and,  going  through  the  recent  numbers  of  the  Experiment  Station 
Record,  took  down  on  the  cards  references  to  all  likely  articles  on  the 
black  knot,  addressed  them,  and  within  a  week  he  had  everything  that 
everybody  knew  about  the  black  knot. 

The  boy  then  went  to  work  out  doors,  hunted  through  the  woods,  and 
collected  the  fungus  on  native  wild  plums  and  cherries,  and  he  made  a 
survey  of  the  city  in  order  to  form  an  intelligent  estimate  of  the  damage 
caused  to  cultivated  fruits.  He  mounted  a  typical  series  of  specimens 
in  a  glass  case,  all  neatly  labeled.  He  studied  the  fungus  with  the 
microscope  and  made  careful  drawings  of  all  the  important  stages  in  its 
growth  and  reproduction.  He  drew  colored  wall  charts  from  his  pictures, 
supplemented  by  those  in  the  books,  and  finally  presented  his  results 
on  the  life  history,  distribution,  and  treatment  of  the  black  knot  in  a 
carefully  prepared  lecture  which  occupied  an  entire  period  of  the  class. 
One  of  his  classmates  happened  to  be  a  reporter  on  a  local  daily,  and 
she  presented  the  subject  to  the  public  in  a  well-written  article  of  about 
two  columns,  and  there  followed  such  a  cleaning  up  of  black  knot  as 
that  city  had  not  seen  in  at  least  fourteen  years. 

"  What  do  you  think  about  that  work  you  did  in  school  on  the  black 
knot  ?  "  the  boy  was  asked  some  years  later.  He  replied,  "  It  exactly 
fitted  my  bent,  and  on  that  account  I  think  I  got  more  real  good  out  of 
it  than  from  any  other  one  thing  in  my  high-school  course."  Better 
than  all,  this  wholesome  little  try  at  real  study  quite  probably  helped 
him  to  decide  what  he  wanted  to  do  for  the  rest  of  his  life. 


352  CIVIC  BIOLOGY 

Special  organizations  and  journals.  The  science  of  our 
countiy  and  the  world  is  not  the  dead,  ciit-and-dried  facts, 
"classified  and  arranged"  in  books.  Real  science  has  been  de- 
fined as  the  "everlasting  struggle  of  the  human  mind  after  the 
truth  "  (Lessing).  Or,  as  Huxley  put  it,  "  Science  is  trained 
and  organized  common  sense."  In  essence,  science  is  the  liv- 
ing, growing,  forward-moving  stream  of  discoveries  —  the  best 
knowing  liow  that  all  the  strugglers  after  truth  are  daily  find- 
ing out.  As  long  as  there  is  progress  it  must  always  be  that 
the  best  that  someone  is  able  to  discover  to-day  will  be  ex- 
celled by  the  discoveries  of  to-morrow,  and  all  that  we  know 
is  but  a  handful  of  pebbles  on  the  shore  of  the  ocean  of  truth 
still  to  be  discovered.  Thus,  in  order  to  make  sure  that  prog- 
ress in  discovery  shall  never  cease,  men  have  organized  univer- 
sities and  research  foundations  and  the  scientific  departments 
and  bureaus  of  the  state  and  national  governments. 

In  addition  to  the  above  are  the  many  special  associations 
of  people  drawn  together  by  mutual  interest  in  various  prob- 
lems. These  associations  contain  our  best  authorities  on  all 
sorts  of  subjects,  and  many  of  them  publish  special  journals  in 
which  members  first  announce  their  discoveries.  It  niay  be 
years  before  these  discoveries  find  their  way  into  the  books  of 
our  libraries.  Hence,  if  we  are  to  find  the  best  knowing  how 
up  to  date,  we  should  learn  what  these  organizations  are  and 
keep  track  of  the  articles  in  their  journals  from  month  to 
month.  We  should  first  make  a  list  of  all  local  organizations 
pertinent  to  civic  biology.  Some  of  these  may  be  branches 
of  larger  societies,  national  or  international.  As  we  learn 
about  their  purpose  and  work  we  should  consider  joining 
any  that  may  seem  desirable,  and  so  begin  to  take  our  places 
in  the  organization  of  the  community  for  progress.  A  few 
of  the  national  organizations  are  indicated  below :  ^ 

1  See  Handbook  of  Learned  Societies  and  Institutions  of  America, 
Carnegie  Institution,  Washington,  D.C..  1908,    The  World  Almanac  gives 


KXOWl^^a  HOW  TO  KNOW  HOW  '66^ 

American  Association  for  the  Advancement  of  Science, 
Dr.  L.  O.  Howard,  permanent  secretary,  Washington,  D.C.,  M^as  founded 
in  1847  and  lias  11,000  members.  The  biological  sections  are  F, 
Zoology;  G,  Botany;  K,  Physiology  and  Experimental  Medicine; 
and  M,  Agriculture.  Sister  organizations  are  the  British  and  French 
associations  for  the  advancement  of  science.  The  official  organ  is 
Science,  published  weekly,  and  sent  gratis  to  all  members  in  the  United 
States  as  part  return  for  the  annual  dues  of  p].  The  Scientific  Monthlji 
(continuation  of  the  Popular  Science  Monthly)  may  be  substituted  if 
preferred. 

American  Society  of  Naturalists  was  first  organized  in  1840 
(reorganized  in  1883)  and  is  the  parent  from  which  many  of  the  more 
special  scientific  societies  have  split  off.    It  has  400  members. 

Central  Association  of  Science  and  Mathematics  Teachers 
(and  many  similar  societies  of  science  teachers).  The  official  organ  for 
all  is  School  Science  and  Mathematics. 

American  Nature  Study  Society,  founded  in  11)08;  official  organ, 
Nature-Study  Revieiv,  Ithaca,  X.Y. 

American  Public  Health  Association.  The  official  organ, 
American  Journal  of  Public  Health,  should  be  in  every  biological  library. 

National  Association  for  the  Study  and  Prevention  of 
Tuberculosis,  founded  in  1904,  has  about  2500  members  and  pub- 
lishes accounts  of  annual  meetings. 

Society  of  American  Bacteriologists,  founded  in  1899,  limited 
to  75  members. 

American  Association  of  Pathologists  and  Bacteriologists, 
founded  in  1900. 

American  Cancer  Hesearc  h  Society,  headipiarters,  1480  AVells 
Street,  Chicago,  111. 

American  Society  of  Zo()LOGists,  founded  in  1902, 187  members. 

Botanical  Society  of  AxMerica,  founded  in  1898,  has  496  mem- 
bers and  publishes  the  American  Journal  of  Botany. 

American  Forestry  Association,  founded  in  1882,  has  15,000 
members  and  publishes  American  Forestry,  Washingix)n,  D.C 

American  Fisheries  Society,  organized  in  1870,  has  700  members. 

National  Association  of  Audubon  Societies,  founded  in  1905, 
now  has  about  4000  members,  with  branch  societies  in  nearly  every 

a  list  of  learned  societies,  with  dates  of  founding,  number  of  members, 
addresses  of  some  of  the  officers,  and  names  of  journals  published,  with 
their  places  of  publication.    Local  libraries  may  supply  more  extended  lists. 


354  CIVIC  BIOLOGY 

state.  The  official  organ  is  Bird  Lore,  edited  by  Frank  M.  Chapman 
and  published  at  Harrisburg,  Pa. 

Amekican  Ornithologists'  Union,  founded  in  1883,  has  1126 
members,  publishes  the  ^w^,  the  official  journal  of  American  ornithology, 
and  also  prints  and  keeps  up  to  date  the  A.  O.  U.  Check-List,  giving  the 
authoritative  names,  popular  and  scientific,  of  all  birds  of  the  United 
States. 

American  Association  of  Economic  Entomologists,  founded  in 
1889,  has  about  500  members;  official  organ,  Journal  of  Economic  Ento- 
mology; Concord,  N.H.  A  complete  set  of  this  journal  ought  to  be 
accessible  in  every  city  and  town  library. 

American  Entomological  Society,  founded  in  1859,  has  140  mem- 
bers and  is  devoted  to  purely  systematic  entomology. 

American  Phytopathological  Society. 

American  Pomological  Society,  founded  in  1849,  has  about  500 
members  and  publishes  biennial  reports  and  special  catalogues  of  fruits. 

American  Society  of  Landscape  Architects. 

American  Genetic  Association  (continuation  of  the  American 
Breeders  Association),  founded  in  1903,  has  about  1200  members  and 
publishes  the  Journal  of  Heredity,  a  monthly  publication  devoted  to 
plant  breeding,  animal  breeding,  and  eugenics.    Washington,  D.C. 

We  have  given  dates  of  founding  and  number  of  mem- 
bers in  order  to  emphasize  the  fact  that  organization  for  know- 
ing how  to  do  things  is  only  just  beginning,  and  that  as  yet 
very  few  are  actively  concerned  with  these  vital  problems. 


CHAPTER  XXXII 

PROGRESS  IN  DISCOVERY 

Anything  which  slieds  light  on  the  nature  of  life  and  of  man  himself, 
his  organic  constitution  and  equipment,  the  laws  and  possibilities  of  his 
mind  and  body,  his  place  and  fate  in  and  relation  to  the  rest  of  the  universe, 
will  appear  immeasurably  more  important  than  the  fate  of  individual  men 
or  nations, —  because  those  things  have  a  fundamental  significance  for  the 
whole  human  race  everywhere  and  for  all  time,  and  likewise  have  the  deep- 
est sort  of  personal  significance  for  everyone  who  is  reflective  enough  to  be 
conscious  of  the  questions  presented  by  his  own  being. 

The  great  battles  of  man  have  not  been  fought  on  Grecian  plains  or 
Spanish  mains  or  over  European  hill  and  dale,  but  within  the  skulls  of  the 
great  investigators,  up  and  down  the  brain  valleys  and  ridges  of  the  great 
tliinkers  and  the  immortal  poets.  It  is  the  great  captains  of  thought  and 
feeling  that  have  led  forth  the  bright-shining  forces  of  the  human  mind  and 
soul  in  the  only  wars  that  have  results  of  permanent  and  universal  impor- 
tance,—  wars  in  which  thoughts,  ideas,  facts,  conceptions  are  deployed 
and  maneuvered  in  phalanxes  and  battalions  to  the  greater  issues  of  our 
human  fate. 

Measured  against  such  Himalayas  of  the  human  mind  and  soul  as  Darwin 
and  Marx  and  Newton,  Napoleon  and  Bismarck  and  Alexander  are  not  even 
among  the  foothills  of  human  significance.  The  publication  of  "The  Origin 
of  Species"  was  a  more  vital  event  in  human  history  than  the  battle  of 
Waterloo.  —  Courtney  Lemon,  Pearson^ s  Magazine,  February,  1917,  p.  183  ff. 

I  am  impressed  with  the  fact  that  the  greatest  thing  a  human  soul  ever 
does  in  this  world  is  to  see  something  and  tell  what  it  saw  in  a  plain  way. 
Hundreds  of  people  can  talk  for  one  who  can  think,  but  •  thousands  can 
think  for  one  who  can  see.  To  see  clearly  is  poetry,  philosophy  and  religion 
all  in  one.  —  Emerson 

y 

Beginning  at  home.  What  biological  discoveries  have  you 
made  ?  Write  down  a  list  of  them  and  tell  in  each  case 
how  you  happened  to  make  the  discovery.  Have  you  told 
anyone  about  them   or  published  your  discoveries  so   that 

365 


356  CIVIC  BIOLOGY 

others  may  be  helped  or  benefited  by  them  ?  How  do  you 
know  that  someone  else  has  not  discovered  the  same  thing 
before  you  ?  Has  your  father  or  mother,  or  some  other 
member  of  3^our  family,  discovered  anything  of  value  to  the 
community  ?  Do  you  know  of  anyone  in  your  town  or  city 
who  has  discovered  anything?  If  so,  can  you  find  the  story 
in  print  or  can  you  go  to  the  person  and  get  the  story  at 
first  hand  ? 

Do  we  know  of  anyone  hi  the  United  States  or  Canada, 
South  America,  Europe,  Asia,  Australia,  or  Africa,  who  has 
made  notable  biological  discoveries  ?.  Who  is  he,  and  what 
is  the  story  of  his  work  ?  ^ 

Kinds  of  discoveries.  Discoveries  may  be  big  or  little ;  they  may  be 
easy,  made  at  a  giauce,  or  even  stumbled  on  by  accident,  though  in 
this  case  one  must  be  intelligent  enough  to  know  what  he  has  found, 
and  be  able  to  think  what  his  discovery  may  mean  to  the  world 
("  Accidents  never  happen  among  the  Hottentots,"  it  is  said) ;  or 
they  may  require  years  of  application,  complicated  apparatus,  and 
costly  laboratories. 

A  little  girl  of  eight,  by  working  from  daylight  till  dark,  discovers 
that  a  bob  white  wdll  eat  1286  rose  slugs  in  a  day,  and  that  when  fed 
abundantly  on  insects,  she  will  lay  eggs.  These  are  valuable  little 
discoveries  and  have  doubtless  influenced  efforts  to  protect  the  bob- 
white.  A  young  woman  devotes  three  years  to  studying  the  foods 
of  the  bobwhite,  and  j)iiblislies  what  is  probably  the  most  complete 
statement  of  the  food  of  any  bird.  This  will  exert  still  more  influ- 
ence for  bird  protection  and  must  hasten  the  day  when  we  shall  have 
enough  bobwhites  to  reduce  weed  seeds  and  insect  i)ests,  and  it  may 
suggest  to  others  similar  studies  of  other  birds.^ 

1  As  early  as  practicable,  when  the  course  is  well  begun  and  interest 
aroused,  bring  up  these  questions  and  make  them  the  main  subject  of  a 
lesson  period  ;  or  appoint  a  date  and  ask  the  class  to  prepare  brief  written 
statements  in  answer  to  the  questions,  and  have  them  read  and  discussed. 
Invite  some  local  discoverer  to  visit  the  class  and  tell  of  his  aims,  methods, 
and  discoveries. 

2  Margaret  Morse  Nice,  ''Food  of  the  Bobwhite."  Journal  of  Economic 
Entomology,  June,  1910,  p.  295ff. 


PKOGKESS  IN  DISCO VEKV  357 

lu  1816  Mrs.  Isabella  Gibbs  discovered  the  Isabella  grape,  and  this 
discovery  is  said  to  have  turned  attention  to  the  culture  of  American 
grapes.  Foui*  years  later  Adlum  discovered  the  Catawba.  "  A  woman 
discovered  it  growing  wild,"  and  we  have  a  vigorous  new  blackberry, 
the  Blowers,  added  to  the  American  list.  Judge  Logan  discovers  a 
chance  seedling,  and  the  Loganberry  is  saved  to  the  world.  ^Ir.  Bull 
works  a  few  years,  and  the  Concord  grape,  and  with  it  a  new  industry, 
is  added  to  American  horticulture.  Mendel  works  eight  years  in  his 
garden,  and  discovers  his  law  of  heredity.  Jenner  and  Darwin  each 
work  twenty  years,  and  the  ideas  of  vaccination  and  the  origin  of 
species  are  placed  at  the  service  of  mankind  for  all  time.  -" 

Importance.  ''  One  single  idea  may  have  more  value  than  all 
the  labor  of  all  the  men,  animals,  and  engines  for  a  century^ 
Here  are  "  mines,"  free  to  all  alike,  that  dwarf  our  Kimber- 
leys,  Nomes,  and  Klondikes  to  the  small  change  of  the  passing 
hour,  whose  output  is  as  much  above  gold  and  diamonds 
as  mind  is  higher  than  matter.  What  kind  of  progress  shall 
we  make  when  all  the  people  of  the  nation  appreciate  this 
point  of  view  and  begin  to  ''  know  enough  to  work  together" 
in  pushing  forward  needed  discoveries  ? 

We  are  approaching  this  degree  of  civic  organization,  as  m 
evidenced  by  the  growth  of  research  departments  in  our  uni- 
versities, by^  our  experiment  stations,  and  by  the  state  and 
national  scientific  departments  and  the  endowed  private  re- 
search foundations.  All  these  are  reaching  down  to  search 
out  talent,  and  ought  to  be  inspiring  every  boy  and  girl  to  the 
most  careful  seeing  and  thinking  of  which  they  are  capable. 
It  is  often  said  that  Pasteur  repaid  to  France  the  entire 
cost  of  her  system  of  public  education,  from  primary  schools 
to  university  and  from  the  beginning  down  to  his  time,  by 
his  one  discovery  of  the  cause  and  prevention  of  silkworm 
disease.  So,  as  such  values  are  being  appreciated,  the  country 
and  world  are  being  searched  for  ability  to  discover.  As  its 
discoveries  are  the  most  priceless  possessions  of  the  race, 
and  since  advance  in  every  field  waits  upon  the  discoverer 


358  CIVIC  BIOLOGY 

to  lead  the  way,  the  scientific  organization  of  the  nation  and 
of  the  world  says,  virtiiallyj  to  every  young  man  and  woman: 
"  Shov)  your  mettle,  demonstrate  your  ability  to  discover  some- 
thing worth  ivhile,  and  equipment  and  ynaterial  support  will 
he  supplied,  and  every  avenue  of  opportunity  will  he  opened  to 
you.  Show  poiver  to  think  and  to  discover,  and  scholarships 
and  fellowships  are  ready  to  place  university  apparatus  and 
laboratories  at  your  disposal 

Historical.  How  have  discoveries  been  made  in  the  past  ? 
How  have  we  learned  to  make  two  blades  of  grass  grow 
where  one  grew  before  ?  How  may  we  make  ten  blades 
grow  where  one  grows  now  ?  What  does  it  matter  that  we 
know  the  value  of  fresh  air,  of  pure  water,  of  good  food; 
that  we  know  that  the  blood  circulates ;  that  we  have  brains 
and  nerves  and  muscles  which  require  exercise  and  care; 
and  that  we  know  about  bacteria  and  parasites  and  the  dis- 
eases they  cause  ?  Do  not  these  things,  and  all  the  rest  for 
which  the  science  of  biology  stands,  mean  the  difference 
between  a  world  of  jungles  and  barren  deserts,  scourged  by 
famines  and  pestilences,  and  a  world  of  farms  and  gardens, 
full  of  happy,  healthy  people? 

Men  have  lived  in  the  world  for  at  least  five  hundred 
thousand  years,  and  astronomers  tell  us  that  the  earth  will 
be  habitable  for  about  five  million  years  to  come.  Is  it  not 
remarkable  how  little  we  know,  how  little  all  the  millions  and 
billions  of  men  and  women  who  have  lived  have  been  able  to 
discover,  —  the  handful  of  pebbles  on  the  shore  of  the  ocean 
of  truth  still  to  be  discovered  ?  How  incredibly  slow  progress 
in  discovery  must  have  been  at  first.  How  much  do  animals 
really  "  see  "  (in  the  sense  in  which  Emerson  uses  the  word) 
of  the  flowers  and  trees,  birds,  insects,  and  fungi  in  the  fields 
they  roam?  And  how  little  the  best  of  us  really  see  of  all 
the  things  that  happen  in  our  fields,  roadsides,  and  gardens. 
Without    doubt    thousands    of    choice   varieties    of   flowers. 


PK0GRES8  IN  DISCOVERY  359 

grains,  fruits,  and  nuts  have  lived  and  died  out  because 
no  one  saw  the  difference  clearly  enough  to  be  able  to 
think  what  they  might  mean  to  the  world;  and  thousands 
more  will  go  the  same  road  until  we  learn  to  see  and 
think  civically. 

Our  present-day  discoverers.  A  number  of  names  referred 
to  in  the  text  under  various  topics  may  be  used  for  refer- 
ence. Our  best  authorities,  as  indicated  in  the  preceding 
chapter,  are  often  discoverers  in  their  respective  fields. 
They  have  probably  won  their  positions  by  some  creditable 
research  work.  Instead  of  trying  to  give  a  list  of  these  it 
is  better  to  gather  the  names  as  they  appear  as  authors  of 
our  best  books  on  birds,  insects,  forestry,  agriculture,  bacteria, 
health  problems,  and  so  on,  or  as  they  come  to  us  from 
month  to  month  in  the  biological  journals  or  scientific  bul- 
letins. We  should  be  thankful  to  our  discoverers  for  what 
they  write,  realizing  that  their  work  requires  patient  appli- 
cation and  great  sacrifice  of  time ;  and  while  we  follow  their 
investigations  in  the  libraries  and  journals,  we  should  be 
very  careful  about  encroaching  upon  their  precious  time  by 
personal  letters.  Perhaps  the  most  discouraging  feature 
of  our  present  situation  is  the  overwhelming  of  our  dis- 
coverer with  inquiries  by  people  who  are  too  indolent  to  go 
to  their  libraries  and  read  what  he  has  written.  For  any 
special  field  we  may  have  one  or  one  hundred  discoverers 
for  our  one  hundred  million  people.  Figure  out  about  how 
much  time  it  would  take  to  answer  a  million  letters. 

Biological  discoverers.  From  the  following  brief  list,  or 
from  any  history  of  science  or  of  medicine,  let  each  member 
of  the  class  choose  some  one  discoverer,  with  whom  he  will 
become  intimately  acquainted  during  the  remainder  of  the 
year.  T^et  him  go  to  the  biographies  and  histories  and  strive 
to  catch  the  spirit  that  prompted  the  man  to  make  his  dis- 
coveries.   Then,  toward  the  close  of  the  year,  let  each  one 


360 


CIVIC  BIOLOGY 


prepare  a  live-iniiiiite  story  to  tell  to  the  class.  By  timing 
these  stories  so  that  they  follow  in  orderly  sequence  we  may 
have  the  history  of  our  science  presented  in  an  effective 
way.  The  aim  is  to  kindle  and  foster  the  spirit  of  these  men, 
so  that  increase  in  knowledge  and  progress  in  discovery  may 
be  assured  from  generation  to  generation.  A  number  of  names 
have  been  included  for  sake  of  completeness.  The  more  im- 
portant and  those  especially  interestmg  on  account  of  their 
contributions  to  civic  biology  are  printed  in  black-faced  type.^ 

1.551     Gesner:  gathered  first  botani- 


B.C. 

540 


500 


460 


400 

350 
320 
320 
300 

A.D. 

79 

160 

1542 

1.548 


Xenophanes  :  first  to  recog- 
nize fossils  as  proving  that 
the  earth  was  formed  nnder 
the  sea  and  rose  out  of  it  1560 

-Heraclitus:    often  called  the       1583 
first   evolutionist ;    he   first 
advanced  the  principle,  irdv-       1 590 
ra  pel  (all  things  flow) 

Enipedocles  :   first  to  suggest      1603 
natural  selection  and   sur- 
vival of  the  fittest  1603 

Hippocrates:  called  *' the  Father 

of  Medicine"  1622 

Aristotle:  founder  of  zoology 

Theophrastus  :  first  botanist         1  ♦>49 

Erasistratus  "1  ^ 

„        ,  .,        ^  first  anatomists      .^^^ 

Herophilus  J  .  In-oO 


Pliny  :  wrote  first  popular  nat-       1661 
ural  history 

Galen :  founded  medical  physi- 
ology 

Vesalius :  founder  of  modern 

anatomy  1667 

Falloppio :  anatomist 


cal  garden  (of  fruits  and 
flowers)  and  first  zoological 
museum 

Eustachio  :  anatomist 

Csesalpinus:  classified  plants 
by  fiowers 

Janssen,  J.  and  Z. :  discovered 
compound  microscope 

Fabricius :  discovered  valves 
in  the  veins 

Harvey :  discovered  circulation 
of  the  blood 

Ascello :  discovered  the  lac- 
teals 

Rudbeck :  discovered  the  lym- 
phatics 

Swammerdam :  first  great  stu- 
dent of  insects  in  relation 
to  plants  and  medicine 

Malpighi:  discovered  the  capil- 
laries in  the  lungs ;  founded 
modern  embryology  by  a 
study  of  the  incubation  of 
the  chick  (1672) 

Leeuwenhoek  :  first  to  see  bac- 
teria 


1  Historical  books  to  which  the  class  should  have  access  for  this  work 
are  Locy,  Biology  and  its  Makers,  New  York,  1908  ;  Baas,  Outlines  of  the 
History  of  Medicine  (translated  by  Handerson),  New  York,  1889  ;  Mial, 
History  of  Biology,  New  York  and  London,  1911. 


PROGRESS  ly  DISCOVERY 


361 


1668  Redi :  disproved  spontaneous 
generation  of  insects  by 
the  discovery  of  eggs  and  1704 
larvae  ;  wrote  ''  Esperienze 
intorno  alia  Generazione 
degl'  Insetti" 

1670  Mayow :    studied  animal  res-       1796 

piration  1 796 

1671  Hooke :    worked  out   micro- 

scopical structure  of  plants       1800 
1680     Borelli :    proved  that   all    the 

movements  of  animals  are 

caused  by  muscles  pulling       1801 

on  bone  levers;  wrote  "De 

Motu  Animalium  " 
1682     Grew :    studied   structure    of 

plants 
1693     Ray  :  classified  plants  1801 

1727     Hales:  investigated  respiration 

of  plants 

1743  Haller:     father    of    modern 

physiology 

1744  Reaumur:  studied  insects  1804 
1749     Buffon  :  wrote  a  natural  his- 
tory 1807 

1 753    LinnjBus  :  classified  plants 

1761  Kolreuter:  studied  hybridiza- 
tion of  plants  1811 

1 76 1  Bonnet :  evolutionist ;  grouped 
animals  in  an  ascending  se- 
ries 1818 

1772     Rutherford  :     discovered    ni 

trogen  1823 

1774  Priestley:    discovered  oxygen 

and  studied  the  breathing 
of  plants 

1775  Spallanzani :  disproved  spon- 

taneous generation  of  bac-  1830 
teria  and  molds  and  demon-  1835 
strated  presence  of  living  1838 
germs  in  the  air 

1789  Galvani :     discovered    animal       1838 

electricity 

1790  Goethe:  worked  out  a  scheme 


for  the  metamorphosis  of 
the  parts  of  plants 

Darwin,  Erasmus :  grandfather 
of  Charles  Darwin ;  wrote 
"Zoonomia,"  a  long  poem 
outlining  evolution  of   life 

Jenner :  discovered  vaccination 

Sprengel :  studied  fertilization 
of  plants 

Cuvier :  studied  comparative 
anatomy ;  wrote  "  Le  R6gne 
animal,"  1817 

Lamarck:  invented  a  scheme 
for  the  evolution  of  animals 
(by  conscious  effort  and  in- 
heritance of  acquired  char- 
acters ;  not  proved) 

Treviranus :  introdviced  the 
name  ''biology"  as  dis- 
tinguished from  ''botany," 
' '  zoology, "  "  physiology, ' ' 
"anatomy,"  etc. 

Humboldt :  studied  distribu- 
tion of  plants 

Rumford,  Count  :  demon- 
strated absorption  of  car- 
bonic acid  by  plants 

Bell,  Charles :  discovered  mo- 
tor and  sensory  nerve  roots ; 
founder  of  modern  neurology 

G,  St.  Hilaire  :  pointed  out 
unity  of  plan  in  animals 

Baer :  discovered  the  law  of 
embryological  development 
(higher  forms  repeat  the 
evolutionary  series  as  the 
embiyos  develop) 

Brown :  described  cell  nucleus 

Dujardin :  studied  protoplasm 

Schleiden :  discovered  the  cell 
as  unit  of  structure  in  plants 

Schwann :  discovered  the  cell 
as  unit  of  structure  in  ani- 
mals 


362   ' 


CIVIC  BIOLOGY 


1839  Agassiz  :  wrote  on  fresh-water 
fishes 

1841  Helmholtz :  discovered  rate  of 
nerve  impulse 

1853  Mohl :  studied  protoplasm  (liv- 
ing substance) 

1857  Pasteur :  studied  fermentation 

1858  Darwin :     reported    his    work 

upon  the  origin  of  species 
by  natural  selection 

1858  Wallace :  reported  his  work 
upon  the  origin  of  species 
by  natural  selection 

1858  Virchow  :  worked  out  cellular 
pathology  ;  founder  of  mod- 
ern pathology 

1863  Huxley:  wrote  "Evidence  as 
to  Man's  Place  in  Nature" 

1863  Lyell:  wrote  ''The  Antiquity 
of  Man" 

1865  Sachs :  studied  structural  bot- 
any 

1865  Mendel:  discovered  the  law  of 
heredity 

1867  Lister :  worked  out  aseptic 
surgery 

1875     Galton:  studied  inheritance 


1875 
1880 
1880 
1886 


1893 
1898 
1888 
1898 
1898 


1900 
1900 
1900 

1903 
1914 
1915 


Hertwig,  O.  :    studied    ferti- 
lization 
Koch :  proved  the  relation  of 

bacteria  to  disease 
Laveran :  discovered  malarial 

parasite  (in  the  mosquito) 
Leuckart:  settled  the  modern 

classification    of    animals ; 

specialized  on  parasites 
Weismann:  studied  germ-plasni 
Reed     1  discovered      relation 
Finlay  \-  between  yellow  fever 
Lazear  J  and  the  mosquito 
Howard :    discovered   relation 

between  typhoid  fever  and 

the  house  fly 

all,  working  inde- 
pendently, redis- 
covered Mendel's 
law  of  heredity 
Stiles :   discovered  hookworm 

in  the  United  States 
Goddard  :  proved  f  eeble-mind- 

edness  a  unit  character 
Stockard :  discovered  influence 

of  alcohol  on  offspring 


De  Vries 
Correns 
Tschermak 


INDEX 


Abalones,  273,  274 

Acetic  acid,  194 

Actinidia  arguta,  8S^  90 

Adder,  326 

Aedes  calopus,  124-128,  130, 132, 134, 
154,  258 ;  breeding  places,  132 ; 
pictures  of  egg,  larva,  pupa,  and 
adult,  124,  125;  relation  of,  to 
yellow  fever,  126,  127 

Aerobic  bacteria,  221 

Agaricacece,  201-205 ;  orders  of,  204, 
205 

Agriculture,  91-106;  breeding  se- 
lected strains,  96-98;  efficiency 
of,  93-96;  fungous  and  bacterial 
diseases,  207-217;  practical  biol- 
ogy of,  91-106;  problems  of  ani- 
mal industry,  102-104;  relation 
of  weeds  to,  68 ;  soil  fertility,  98- 
100 ;  value  of  land,  100-102 

Alcohol,  165,  191;  influence  of,  on 
germ  plasm,  340,  341,  343;  manu- 
facture of,  194,  195 

Alfalfa,  101,  212,  223 

Algse,  188 

Alkaloid,  201 

Alligator,  321,  323 

Alligator  terrapin,  324 

Almond,  165 

Amanita,  73,  76,  200-205;  descrip- 
tion and  picture,  201,  202 

American  birds,  orders  of,  38-40, 
42-51 ;  pictures  of,  22 

American  Bison  Society,  171 

American  cockroach,  154 

American  crow,  48 


American  elm,  84 

American  false  hellebore,  76 

American  goldfinch,  49 

American  goshawk,  45 

American  insects,  253 

American  laurel,  75 

American  lobster.    See  Lobster 

American  lotus  lily,  307 

American  magpie,  48 

American  mammals,  169-172 

American  osprey,  45 

American  redstart,  50 

American  robin,  51 

Amphibia,  313-320,  325 

Anaerobic  bacteria,  221 

Animal  diseases,  110 

Animal  industry,  102-104 

Animal  parasites,  253-269 

Anopheles,  127,  130,  131,  134,  154, 
257 ;  breeding  places  of,  132 ;  pic- 
ture of  eggs,  larva,  pupa,  and 
adult  of,  125;  relation  of,  to  ma- 
larial fever,  123,  124 

Antelope,  169,  261 

Anthracnose,  210,  212,  215 

Anthrax,  235,  236,  248 

Antimeningitis  serum.  111 

Antisepsis,  248 

Antitoxins,  243,  247-249 

Antivenins,  329 

Ants,  141-147;  carpenter  ant,  146, 
147 ;  economic  importance,  141 ; 
food,  143 ;  rearing  of,  in  labora- 
tory, 145-147  ;  red  ants,  155  ;  spe- 
cial senses,  143 ;  warfare,  144 ; 
white  ants,  153,  155 


363 


364 


CIVIC  BIOLOGY 


Apanteles,  enemies  of,  140 

Aphids,  61,  142,  152,  156 

Apoplexy,  232 

Apparatus,  11 

Appendicitis,  234 

Apple,  94,  165 

Apple  Day,  299 

Apple  of  Peru,  75 

Apple  tree,  blight  of,  212,  213,  216 ; 

enemies  of,  155,  156 
Aquaria,  10,  315 ;    cement  for,  15 ; 

making  of,    12-15 ;    management 

of,  299-303 
Aquatic  duck  foods,  307 
Arachnids,     problems    of     spiders, 

mites,   and   ticks,    163-168 
Arbor  Day,  299 
Arbor  vitae,  59,  165 
Army  worm,  156,  317 
Arsenate  of  soda,  71 
Arsenic,  poison  for  rats,  180 
Artesian  wells,  219 
Asepsis,  248 
Asiatic  poppy,  73 
Asparagus  beetle,  156 
Asters,  86 

Atlantic  salmon,  309 
Atlantic  squid,  284 
Australian  duck-bill,  169 

Bacteria,  176,  214;  blight  or  wilt 
from,  215 ;  control  of  bacterial 
diseases,  231-251 ;  culture  of, 
224-230 ;  distribution  and  forms 
of,  218 ;  fungous  and  bacterial 
diseases  of  plants,  207-217;  gen- 
eral discussion  and  treatment  of, 
186-191,  218-251  ;  kinds  of,  218, 
220,  221,  234,  236,  242;  labora- 
tory methods  and  experiments, 
224-230;  parasitic,  187;  picturas 
of,  236;  reproduction  of,  220,  221; 
saprophytic,    221;    size    of,   218; 


symbiotic,    187,    221 ;    venomous 

forms  of,  234 ;  work  of,  221 
Bacterins,  248 
Badger,  171 
Bald  cypress,  59 
Bald  eagle,  45 
Balsam,  59 
Baltimore  oriole,  48 
Banana,  food  for  mosquitoes,  131 
Bank  swallows,  49 
Banostine  Belle  de  Kol,  103 
Barium  carbonate,  179 
Bark  disease,  247 
Barn  swallows,  49 
Barnacles,  287 
Basket  willow,  307 
Basses,  309 
Basswood,  59,  82 
Bats,  129,  169 
Bean  blight,  215 
Bear  corn,  76 
Bears,  165,  169 
Beaver,  171,  172,  261 
Bedbug,  154,  236 
Beech,  59 

Bees,  152,  153,  158;  honeybee,  157 
Beetles,  20,  21,  153-156,  317,  318 
Belladonna,  73 
Belted  kingfisher,  46 
Benzine,  165 
Bindweed,  71 
Biological  library,  16,  17;  using  of , 

349-351 
Biology,  instruction  and  research  in, 

346 
Birch,  59,  83,  84 
Bird  Day,  299 
Bird  fountain,  29 
Birds,  22-53,  313,  317  ;  adaptation  of, 

to   environment,   37 ;    attracting, 

28,  31,  33;   conservation  of,   63; 

destruction  of  insects,  23,  24,  25  ; 

divisions  of,  32 ;  economic  value 


INDEX 


865 


of,  24 ;  food  of,  24,  25,  30,  34,  42 ; 
food  chart,  33;  methods  of  bird 
study  and  special  problems,  35- 
53 ;  migration,  29,  30,  31 ;  number 
needed,  28 ;  orders  of,  22,  37-53 ; 
outdoor  laboratory  work,  25-31 ; 
plan  of  course,  23 ;  topics  for  study, 
31,  32 ;  topography  of,  37 ;  winter 
feeding  of,  31 ;  work  suggested,  31 

Bison,  169,  171 

Bitter  rot,  210,  212,  213 

Bittersweet,  76 

Bivalves,  274 

Black  basses,  309 

Black  carpet  beetle,  154 

Black  cherry,  59,  75 

Black  death,  175,  177,  233 

Black  flies,  113 

Black  gum,  59 

Black  knot,  207 

Black  mustard,  70 

Black  nightshade,  76 

Black  rot  of  cabbage,  212 

Black  snakes,  326 

Black  walnut,  59,  60,  82,  83  ;  pictures 
of,  61,  66 

Black-and-white  warbler,  50 

Blackberry,  94 

Black-billed  cuckoo,  46 

Blackbirds,  34,  48 

Blackleg,  248 

Blight,  on  bean,  215 ;  fire  blight,  212  ; 
on  pear  and  apple,  212,  213  ;  on 
potato,  210,  215 

Blister,  or  oil,  beetle,  156 

Blood,  good  and  bad,  344 

Blood-sucking  conenose,  154 

Blowfly,  154,  318 

Blowing  adder,  326 

Blowing  viper,  327 

Blue  crabs,  287,  292 

Blue  Jay,  48 

Bhieback  salmon,  309 


Bluebird,  49,  51 

Bluebottle,  112,  154 

Bluegill,  299,  306,  307,  309 

Blue-tailed  lizard,  825 

Bobolink,  48 

Bob  white,  34,  41,  42,  53,  332 

Body  louse,  154 

Boils,  233,  234,  236,  248 

Bollworm,  156 

Bordeaux  mixture,  209,  217 

Borer  beetle,  155 

Botflies,  113,  157 

Bovine  malaria,  257 

Bovine  tuberculosis,  110,  223 

Box  tortoise,  324,  325 

Bright' s  disease,  232 

Broad-leaf  laurel,  75 

Bronchitis,  234,  235 

Bronzed  grackle,  48 

Brook  trout,  309 

Brooks's  law,  291, 292, 808 ;  applied  to 
food  and  game  fishes,  308 ;  applied 
to  the  lobster  problem,  286, 291, 292 

Brown  creeper,  51 

Brown  rot,  207,  210,  211 

Brown  thrasher,  51 

Brown-tail  moth,  20,  156,  160-162 

Bubonic  plague,  2,  107,  175-177,  215, 
234,  248 

Bugbane,  76 

Bull  thistle,  71 

Bullfrogs,  313,  315,  316,  317,  319 

Burdock,  71,  72 

Burrowing  rootstocks,  71 

Butter  clam,  278 

Butterflies,  153;  cabbage,  21, 136-140 

Butternut,  59 

Cabbage,  94,  98 ;  black  rot  of,  212 
Cabbage  butterfly,  21,  136-140;  con- 
trol, 138-140;  dispersal,  137;  fe- 
cundity, 136 ;  life  history,  136-137 ; 
natural  enemies,  186 


366 


CIVIC  BIOLOGY 


Cabbage  caterpillar,  25 

Cabbage  looper,  166 

Cabbage  and  radish  maggot,  166 

Cabbage  worm,  156 

Caddis  flies,  153 

Calcium,  98,  99,  100 

Calcium  chloride,  249 

Calico  bush,  75 

Calico  mosquito,  127 

California  poison  sumac,  75 

Camel,  261 ;  itch  mite  of,  166 

Campaign,  anti-fly,  119,  120;  anti- 
mosquito,  134,  135 

Camphor  tree,  73 

Canada  goose,  39 

Canada  thistle,  71 

Cancer,  232,  234 

Canker,  215 

Cankerworm,  50,  51,  165 

Cannas,  86 

Caper  spurge,  76 

Carabid  beetle,  317 

Carbolic  acid,  71,  249 

Carbon,  98 

Carbon  bisulphide,  used  in  destroy- 
ing rats,  181 

Carbonic  acid,  187,  191,  194,  195 

Cardinal  flower,  67,  154,  306,  307 

Carpenter  ant,  directions  for  study 
of,  146,  147 

Carpet  beetle,  154 

Carrot,  106 

Casein,  189 

Case-making  moth,  154 

Cases,  insect-rearing,  10 

Cashes,  76 

Cat,  166,  182,  256,  263,  267  ;  relation 
of,  to  diphtheria,  245,  246 

Catbird,  61 

Caterpillar,  46 

Catfish,  306,  307,  309 

Cattle,  171 

Cattle  tick,  167 


Cedar,  83 

Cedar  wax  wing,  50 

Cephalopods,  274,  284 

Cerebral  hemorrhage,  232 

Cerebrospinal  meningitis,  248.    See 

also  Meningitis 
Cestodes,  260,  262 
Chameleon,  325 
Chara,  307 
Cheese,  Camembert,  189 ;  Limburger, 

189 ;  Roquefort,  189  ;  Stilton,  189 
Cheese  or  ham  skippers,  164 
Cherry  bird,  60 
Cherry  louse,  156 
Chestnut,  69,  60,  82,  83 
Chestnut-bark  disease,  216 
Chewink,  49 
Chickadee,  60,  51 

Chickens  sick  with  limber  neck,  122 
Chicks  killed  by  rats,  174 
Chickweed,  70,  71 
Chiggers,  165 
Children's  bane,  76 
Chimney  swift,  47 
Chinchbug,  42,  156 
Chinese  pernicious  scale,  156 
Chinook  salmon,  309 
Chipping  sparrow,  47,  49 
Chlorine,  98,  114 
Cholera,    107,   236,   236,   245,   248; 

fowl,  110,  233  ;  hog,  110,  248 
Cholera  infantum,  20,  107 
Cicadas,  153 
Cinchona,  73 
Citronella,  128 
Civic  biology,  definition  of,  1 ;  plan 

of  course,  3-9 
Civic  fly  campaign,  119,  120 
Civic  forestry,  56-66    . 
Clam,  274  ;  butter,  278  ;  gaper,  278  ; 

giant,  278  ;  hard,  273  ;  life  history 

of,  278,  279  ;  little-neck,  277;  razor, 

273  ;  soft,  273  ;  surf,  273 


INDEX 


36' 


Cliff  swallows,  49 

Clothes  moths,  154 

Clover  mite,  165 

Cluster  fly,  154 

Clydesdales,  333 

Coal  oil,  71 

Coast  newt,  320 

Cobra,  327 

Cocaine,  343 

Cockles,  conchs  of,  273 

Cockroaches,    153,    154.      See    also 

Roaches 
Cod,  309 

Codling  moth,  21,155;  type  for  study,  6 
Coffee,  344 

Cold,  233,  234,  246,  250,  251 
Cold  storage,  269 
Coleoptera,  153 
Collecting  nets,  12 
Colorado  blue  spruce,  83 
Colorado  potato  beetle,  156 
Common  stramonium,  75 
Conchs,  273,  274 
Concord  grapevine,  339 
Condiments,  71 
Conifers,  59 
Consumption,  234 
Contact  infection,  246 
Coontail,  or  hornwort,  307 
Cooper's  hawk,  45 
Copepods,  287,  288,  289 
Copperas,  114 
Copperhead,  322,  327 
Coral  snake,  328 
Corn,  93,  94,  95 
Corn  cockle,  75 
Corn  snake,  326 

Corn-ear  and  tomato  worm,  156 
Corn-root  aphis,  156 
Corrosive  sublimate,  249 
Cotton,  93  ;  pests  of,  156 
Cotton  worm,  156 
Cottonmouth,  327 


Cottonwood,  59,  165 

Cottony  cushion  scale,  20,  156 

Cottony  maple  scale,  156 

Couch  grass,  71,  72 

Cow,  102,  103,  165,  263 

Cowbane,  75 

Cowbird,  47,  48 

Cowpox,  258 

Cowslip,  306,  307 

Crab,  287,  292-294 

Crab  apple,  82 

Crappies,  306,  309 

Crawfish,  287,  293,  294,  306,  307, 
317,  318 

Crested  flycatcher,  47 

Crickets,  153 

Crimson  Rambler  rose,  97 

Crocodiles,  321,  323 

Crocus,  197 

Crops,  standards  and  percentage  of 
efficiency  of,  93,  96 

Cross-pollination,  157,  158 

Croton  bug,  154 

Croup,  232 

Crown  gall,  212,  216 

Crows,  48 

Crude  drugs,  71,  73 

Crude  sulphuric  acid,  71 

Crustacea,  285-294,  315,  324  ;  prod- 
ucts of,  287 

Cuban  pine,  59 

Cuckoo,  food  of,  25,  46 

Culex  mosquito,  124,  125,  127,  128, 
129,130,131,132;  breeding  places, 
132  ;  extermination  of,  128  ;  flight, 
128  ;  picture  of  eggs,  larva,  pupa, 
and  adult,  129,  130 

Curculio  beetles,  155 

Curled  dock,  70,  71 

Currant  borer,  156 

Currant  worm  or  slug,  157 

Cuttlefishes,  274 

Cutworms,  25,  156,  317 


368 


CIVIC  BIOLOGY 


Dahlia,  86 

Dandelion,  72 

Dandruff,  236 

Darwin,  Charles,  330,  331,  333,  338 

Datura  stramonium,  72,  75 

Death-cup  mushroom,  76 

Death-of-man,  75 

Deer,  169,  171,  172,  261,  263 

Deer  farming,  172 

Deer  flies,  113 

Delaware  grape,  85 

Devilfishes,  274 

Devil's  apple,  75 

Devil's-bite,  76 

Diamond-backed  terrapin,  324 

Diarrhea,  232,  233,  234 

Diphtheria,  177,  232,  234,  235,  236, 
239,  243,  245,  246,  248,  250,  251 

Diptera,  153,  155 

Discoverers,  biological,  359-362 ; 
present-day,  359 

Discovery,  history  of,  358,  359 ;  im- 
portance of,  357-358 ;  kinds  of, 
356,  357 ;  progress  in,  355-362 

Distemper,  248 

Dock,  72 

Dodder,  188 

Dodo,  42,  43 

Dog,  165,  182.  257,  263  ;  influenceil 
by  alcohol,  341 ;  itch  mite  of,  166  ; 
as  a  transmitter  of  rabies,  256 

Dog  tick,  168 

Dogwood,  75 

Dourine,  259 

Doves,  34,  42,  43 

Downy  woodpecker,  6,  46 

Dragon  flies,  129,  153  ;  nymphs  of, 
as  enemies  to  young  mosquitoes, 
131 

Drop,  a  disease  of  lettuce,  210 

Drug  plants,  72 

Drug-store  beetles,  155 

Dry  rot,  or  stem  blight.  216 


Duck,  38  ;  attacked  by  rats,  174 
Duck  hawk,  45 
Duck  potato,  or  wapata,  307 
Duckmeat  (Lemna),  307 
Duck-retter,  76 
Dwarf  larkspur,  76 
Dysentery,  20,   107,   110,  233,  235, 
245,  256 

Eagle,  44 

Earthworm,  25 

Eczema,  236 

Effluvia,  237 

Egg  record,  104 

Egret,  40 

Elderberry,  86 

Elk,  169,  171 

Elm,  59,  82-84,  165 

Elm-leaf  beetle,  21,  156 

Elodea,  307 

Endocarditis,  232 

English  sparrow,  45,  49,  50,  182 

Enteritis,   107,   232,   234,   235.    See 

also  Gastro-enteritis 
Entomostraca,  287 
Eohippus,  333 
Erysipelas,  234,  251 
Eugenics,  344 
European  root  disease,  212 
Evening  primrose,  70 
Evolution,  338 
Excursions,  plans  for,  7,  8,  9 

Facultative  bacteria,  221 
Fall  webwonn,  155 
Farm  crops,  relative  fertility  of,  101 
Feeble-mindedness,  causes  and  con- 
sequences of,  344 
Felons,  233 
Fence  swift,  325 
Fermentation,  191,  194,  195,  196 
Ferns,  188 
Field  mice.  34.  44 


INDEX 


369 


Field  observations  and  records,  4,  5 

Filariasis,  253 

Filth-disease  fly,  107 

Filth-disease  infections,  107,  110 

Fire  blight,  212 

Fish  hatchery  made  from  tumbler, 
303 

Fish  hawk,  45 

Fish  ponds  on  farms,  296 

Fishes,  39,  306,  317;  classification 
and  species,  304 ;  economic  and 
civic  value,  310 ;  enemies  of  mos- 
quitoes, 131  ;  habits  and  spawning 
seasons,  308  ;  problems  of  fish  and 
fishing,  295-311 

Fishes  Day,  299 

Flat-headed  apple-tree  borer,  155 

Flatworms,  255,  260 

Flea,  182,  '  236,  240  ;  burrowing 
(chigoe),  155  ;  cat,  154  ;  dog,  154  ; 
hen,  155  ;  rat,  154 

Flea  beetle,  156 

Flesh  flies,  112 

Flicker,  46 

Flies,  107-122,  152,153, 182,  242,  245, 
261,  268,  332 ;  blood-sucking,  259  ; 
blowfly,  154,  318  ;  bluebottles,  112, 
154  ;  botflies,  113,  157  ;  campaigns 
against,  110,  111,  117,  118,  120, 
122 ;  cluster  fly,  154 ;  fecundity 
of,  117;  fruit  fly,  154  ;  greenbottle, 
112,  154;  hibernation  of,  117; 
hornfly,  113,  121,  157  ;  kinds,  111, 
112,  113,  118,  154,  318;  life  his- 
tory of,  116 ;  nets  for  catching, 
119 ;  relation  of,  to  disposal  of 
waste,  114,  115  ;  screens  for,  futil- 
ity of,  110  ;  stable,  108, 109  ;  traps 
for  outdoors,  115, 118  ;  tsetse,  236  ; 
work  of,  107,  110 

Flood  plane,  56 

Floods,  cause  of  and  damage  from,' 
55,  56 


Flowering  bean,  86 

Flowering  quince,  97 

Flowers  in  relation  to  landscaping, 
86 

Flukes,  260 

Flycatchers,  47 

Fomites,  237,  238 

Food,  law  of  absorption,  189,  190 

Foot-and-mouth  disease,  110, 233, 256 

Forest  fires,  causes  of,  61,  64  ;  dam- 
age from,  55,  62,  64;  laws 
regulating,  66 ;  relation  of,  to 
tree-planting,  65 

Forest  preserves,  171 

Forestry,  annual  growth  of  trees,  55  ; 
consumption  of  wood,  55 ;  effects 
of    adequate     planting,    57,    58 
natural    enemies    of    trees,    156 
study  of  local   problems   of,  58 
study  of  trees  and  civic  viewpoint, 
54-66 

Formalin,  as  germicide,  249  ;  use  of, 
to  prevent  potato  blight,  216 

Formicary,  145 

Foul  brood,  233 

Fowl  cholera,  110,  233 

Fowl  tuberculosis,  110 

Fox  sparrow,  49 

Foxglove,  78 

Foxtail,  70 

Fresh-water  mussel,  273,  279,  281 

Fringed  gentian,  67 

Frog,  39,  306,  313,  314,  315,  317, 
318,'  320 ;  possibilities  of  culture, 
318 

Fruit  fly,  154 

Fungi,  73,  97,  186-191;  bacteria, 
general  treatment  of,  218-251 ; 
fungous  and  bacterial  diseases  of 
plants,  207-217;  molds  and  mil- 
dews, 197-199;  mushrooms,  poi- 
sonous and  edible,  200-206 ;  yeasts, 

m-197 


370 


CIVIC  BIOLOGY 


Fungous  diseases,  207-213;  damage 
from,  207 ;  organizing  for  the  con- 
trol of,  217 

Fur  farming,  172 

Fur-bearing  animals,  3 

Gall  insects,  157 

Game,  3;  killed  by  rats,  174 

Game  birds,  3 ;  conservation  of,  53 

Gaper  clam,  278 

Gapeworm,  254,  266 

Garden  slug,  282,  283 

Garden  spurge,  76 

Garter  snake,  326 

Gartered  plume  moth,  156 

Gastro-enteritis,  111.  See  also  Enter- 
itis 

Gastropods,  274,  282,  283,  284 

Geese,  38,  53,  325 

Genetics,  330,  337  ;  organized  study 
of,  339 

Gentians,  67,  306 

Geoduck,  278.    See  also  Giant  clam 

Geometrical  increase,  illustrated  by 
diagram,  331  ;  law  of,  331-332 

Germ  plasm,  338 ;  injury  to,  340,  343 

German  roach,  154 

Germicides,  248 

Giant  clam  (geoduck),  278 

Gila  monster,  325 

Ginseng,  73 

Glanders,  235 

Gnat  catcher,  51 

Gnats,  111,  153 

Goat,  169,  261 ;  itch  mite  of,  166 

Golden  plover,  40 

Goldenrod,  86 

Goldfinch,  49 

Gonococcus  infection,  240 

Gonorrhea,  107 

Gopher,  30,  34,  44 

Gopher  plant,  76 

Gopher  snake,  326 


Gopher  tortoise,  325 

Goshawk,  45 

Grackle,  48 

Grain,  pests  of,  156 

Grain  aphis,  or  green  bug,  156 

Grape,  6,  85,  87,  88,  94 

Grape-berry  moth,  156 

Grapevine  root  beetle,  156 

Grasshoppers,  25,  152,  153,  156,  318 ; 

diagram  of,  151 
Great  horned  owl,  46 
Great  laurel,  76 
Green  frog,  315,  316 
Green  turtle,  324 
Greenbottle  fly,  112,  154 
Grippe,  234,  236,  250,  251 
Ground  itch,  268 
Grouse,  40 
Grubb,  94 

Guatemalan  ant,  141 
Guernsey,  103 
Guinea  pigs,   experiments  showing 

influence  of  alcohol  upon,  340 
Gull,  38 
Gypsy  moth,  20,  69,  148,  156,  159, 

160,  162,  317 

Hair  snakes,  265 

Hairy  woodpecker,  46 

Hard,  or  little-neck,  clam,  277 

Hardy  perennials,  86 

Hares,  165,  169 

Harlequin  snake,  328 

Harvest  mites,  163.  165 

Harvestmen,  164 

Hawks,  30,  34,  44,  45 

Hawksbill,  324 

Heath  hen,  42 

Heliotrope,  86' 

Hellebore,  76 

Hemiptera,  153 

Hemlock,  59,  75,  83 

Hen.  104 


INDEX 


371 


Hen  flea,  155 

Herbicides,  71 

Herbs,  71,  73 

Heredity,  laws  of,  330,  334,  338 

Hermit  thrush,  61 

Heroin,  343 

Heron,  39,  40 

Herring  gull,  38 

Hessian  fly,  21,  156 

Hickory,  59,  60,  82 

High  laurel,  75 

"Hill  Folk,  The,"  345 

Hip  disease,  234 

Hog  and  fowl  cholera,  110,  233 

Hollyhocks,  86 

Holstein,  103 

Honey  locust,  82 

Honeybee,  157;  relation  of,  to  tree 
fertility,  157 

Hookworm,  107,  253,  254,  256,  268 

Hookworm  disease,  254,  268 ;  pic- 
tures of  victims  of,  252 

Horehound,  72 

Horn  fly,  113,  157  ;  life  history,  121 

Horned  lark,  48 

Horned  toad,  325 

Horse,  165,  257,  261 ;  itch  mites  of, 
166 

Horse  botfly,  157 

Horse-chestnut,  75 

House  ant,  155 

House  cricket,  154 

House  fly,  20,  317;  breeding  places, 
113, 114 ;  fecundity,  18 ;  relation  of, 
to  filth,  116,  118.    See  also  Flies 

House  pets,  245 

House  wren,  51 ;  food  of,  25 

Household  insects,  154,  155 

Hydrogen,  98 

Hydrophobia,  256 

Hymenoptera,  153,  156 

Hypochlorites,  249,  251 

Hypochlorous  acid,  249 


Human  flea,  154 
Human  mite,  166 
Human  tapeworm,  260 
Humming  bird,  6,  46 
Humming-bird  moth,  155 

Ichneumon  fly,  136 

Imported  currant  fly,  21 

Indian  corn,  95 

Indian  pipe,  188 

Indian  poke,  76 

Indian-meal  moth,  155 

Indigo  bunting,  49 

Infantile  paralysis,  20,  122,  236,  256 

Infection,  110,  122,  246 

Inflammation,  234,  236 

Inflammatory  fever,  248 

Influenza,  235 

Insect-catching  bottle,  131 

Insecticides,  152 

Insectivorous  birds,  44 

Insects,  44,  51,  97,  176,  250,  253,  313, 
315 ;  attacking  animals,  157 ;  bene- 
ficial, 157 ;  cases  for  mounting,  11 ; 
classification  of,  150,  151,  152 ; 
damage  and  loss  from,  19, 20,  24 ; 
fecundity  of,  18 ;  household,  154, 
155 ;  injurious  to  vegetation,  155, 
156,  157;  literature  on,  149;  nets 
for  catching,  11, 12  ;  orders  of,  153; 
parts  of,  152 ;  size  of,  18 ;  work 
of,  18 ;  work  of  controlling,  20 

Ireland,  famine  in,  208 

Iris,  86 

Iron,  71,  98,  99 

Ironwood,  59 

Itch  mites,  166 

Itchweed,  76 

Ivy,  75,  76 

Ivy  wood,  75 

Jack  pine,  59 
JamCvStown  lily,  75 


372 


CIVIC  BIOLOGY 


Jamestown  weed,  75 

Japanese  maple,  83 

Japanese  quince,  89 

Japanese  snowball,  89 

Jays,  48 

Jimson  weed,  72,  75 

Jukes  family,  345 

Junco,  49 

June  beetles,  153,  156 

Kallikak  family,  diagram  outlining 

history  of,  342 
Kalmia,  75 
Kangaroo,  261 

Kerosene,  remedy  for  dog  tick,  168 
King  cobra,  328 
Kingbird,  47 
Kingfisher,  46 
Kinglets,  51 
Kissing  bug,  154 

Laboratory,  outfit  of,  10 

Laboratory  work,  outdoor,  25 

Lace  wings,  153 

Lady  beetle,  153;  Chinese,  20-21 

Lady's-slipper,  67 

Lamb's-quarters,  69,  70 

Lamellibranchs,  279 

Lancaster  elm,  78,  79,  80 

Land,  relative  value  of,  100,  101 

Land  salamander,  315 

Land  snail,  283 

Landscape  gardening,  77-90 

Larch,  83 

Larder  beetles,  155 

Lark,  34,  48 

Larkspur,  76 

Late  blight,  or  rot,  216 

Laurel,  75 

Lawn,  71 

Lead  acetate,  antidote  for  poison  of 

ivy,  oak,  and  sumac,  74 
Leaf  spot,  212 


Leaf-eating  sawfiies,  157 

Least  flycatcher,  47 

Leghorn,  w^hite,  104 

Legumes,  188,  222 

Lenma,  307 

Leopard  frog,  315,  316,  319 

Leprosy,  107,  234,  251 

Lettuce,  94 

Library,  using  of,  349 

Lice,  153,  154 

Life,  practical  laws  of,  330-345 

Lilies,  86 

Lily,  94 

Limber  neck,  chickens  sick  with,  122 

Lime,  99,  100,  102,  223 

Lincoln,  92,  95 

Linden,  82 

Little  black  ant,  155 

Little  house  fly,  112 

Liver  fluke,  261 

Lizard,  321,  323,  325 

Loblolly  pine,  59 

Lobster,  286-294 ;  propagation,  289 

Lockjaw,  234,  248 

Loco  weed,  73,  74 

Locust,  59,  82 

Loggerhead  turtle,  324 

Long-leaf  pine,  59 

Loons,  38 

Louse,  154,  156 

Lupus,  234  ' 

Li/coperdacem,  203 

Lynxes,  160 

Magnesium,  98,  99 

Magpie,  48 

Maidenhair  fern,  67 

Malaria,  20,  123,  124,  125,  134,  236, 

252,  254  ;  bovine,  257  ;  prevention 

of,  133,  257 
Malarial  mosquito,  154 
Malarial  parasites,  256,  257 
Mallard  duck,  39,  306 


IXDEX 


378 


Mammals,  34,  167,  176  ;  American 
Mammal  Problems,  169-172 ; 
orders  of,  with  pictures  of  habi- 
tats, 170 

Man,  176 

Manganese,  98 

Manure,  barnyard,  70  ;  disposal  of, 
115 ;  relation  of,  to  flies,  114,  115 

Maples,  59,  88 

Marigold,  86 

Markweed,  75 

Marsh  hawk,  45 

Marsh  wren,  51 

Martin,  49,  171 

Massasaugas,  327 

Mayweed,  70 

Meadow  lark,  48 

Meal  worm,  155 

Measles,  36,  215,  232.  283,  236,  239, 
247,  256 

Medicinal  plants,  71 

Mendel's  law,  330,  337,  344,  345; 
diagram  illustrating,  335,  338 ; 
history  of,  336 

Meningitis,  107,  234.  See  also  Cere- 
brospinal meningitis 

Meningococcus,  234 

Mercuric  acid,  cure  for  potato  scab, 
216 

Mercuric  chloride,  240 

Mercury,  75 

Miasms,  237 

Mice,  30,  34,  44,  174.  182.  183,  184, 
185,  245,  267 

Mildew.   See  Molds 

Milk,  pasteurizing  of,  244 

Milkweed,  69,  71 

Minks,  169 

Mission  grape,  85 

Mites,  163-168,  236;  clover  mite, 
'  65  ;  harvest  mite,  163,  165  ;  itch 
•  lite,  166  ;  poultry  mite,  167;  red 
V  aite,  129  ;  sheep-scab  mite,  166 


Moccasins,  327,  328 

Mocking  bird,  50,  51 

Molds  and  mildews,  97, 186, 189, 191, 
193,  194,  210 ;  botanical  position 
and  structure  of,  197,  198  ;  obser- 
vation of  and  experiments  with,  199 

Mole  plant,  76 

Moles,  30,  165,  171 

Mollusca,  classification  of,  274 

Mollusks,  271-284 

Mongolian,  or  ring-necked,  pheasant, 
42 

Monkey,  263 

Moose,  169 

Morphine,  343 

Mosquito,  20,  111,  113,  119,  123-135. 
153,  154,  164,  182,  236,  240,  253, 
257,  332  ;  breeding  places  of,  131, 
132  ;  kinds  of,  125 ;  life  history 
of,  124, 128  ;  methods  of  extermi- 
nation of,  133  ;  natural  enemies 
of,  129,  131  ;  planning  of  cam- 
paign against,  134,  135 

Mosses,  188 

Moth,  153,  318  ;  case-making,  154  ; 
clothes,  154 ;  codling,  6,  155.  See 
also  Brown-tail  moth.  Grape-berry 
moth,  Gypsy  moth,  White-marked 
tussock  moth 

Mountain  laurel,  75,  86 

Mountain  sheep,  169 

Mourning  dove,  43,  44 

Mucket  shells,  307 

Mud,  or  pond,  terrapins,  325 

Mud  puppies,  314,  320 

Mulberry,  o9 

Mullein,  71,  72 

Mumps,  247 

Mushrooms,  73,  186,  189,  197,  210 ; 
cause  of  root  rot,  211  ;  classifica- 
tion of,  203-206 ;  poisonous  and 
edible,  200-206 

Musk  grass  (Charu),  307 


374 


CIVIC  BIOLOGY 


Muskrat,  171 

Muskrat  weed,  75 

Musquash  root,  76 

Mussels,  273,  274,  279-281,  300 

Mustard,  70,  72 

Mutation,  338 

Myriapods,  317 

Myriophyllum,  307 

Mytilus,  276,  277,  278,  279 

Nagana,  or  tsetse-fly  disease,  259 

Nam  family,  345 

Nasturtium,  86 

Native  plants,  conservation  of,  67 

Natural  selection,  law  of,  335 

Nautilus,  274 

Nematodes,  264,  265,  266 

NephriMs,  232 

Nets,  collecting,  11  ;  fly,  119 ;  ma- 
terials for  making,  12 

Neuroptera,  153 

Newts,  131,  314,  320 

Nicotine,  343 

Niggerhead,  280 

Nighthawk,  47 

Nightshade,  76 

Nitrates,  102 

Nitrifying  bacteria,  222 

Nitrogen,  47,  98-101,  187 

Norman  Percherons,  333 

Notebook,  instructions  for  keeping, 
in  field  and  laboratory,  11 

Noxious  mammals,  30,  44 ;  destruc- 
tion of,  44 

Nuthatches,  51 

Nuts,  importance  of,  and  suggestions 
for  growing,  60 

Oak,  69,  83,  84 

Oats,  93 

Octopus,  274 

Oil,  coal,  71  ;  olive,  128  ;  of  tar,  128 

Onion  maggot,  156 


Ophthalmia,  107 

Opium,  343 

Opsonic  index,  248 

Orchard  orioles,  food  of,  25 

Orchard  pests,  155 

Oregon  water  hemlock,  76 

Oriental  cockroach,  154 

Orioles,  48 

Orthoptera,  153 

Osprey,  45 

Otter,  171 

Ovenbird,  50 

Owls,  30,  34,  44 

Oxygen,  98,  194 

Oyster,  271,  274,  279;  Atlantic,  273  ; 

Pacific,  273  ;  producing  sickness. 

272 
Oyster  drill,  282 
Oyster-shell  scale,  166,  332 

Pacific  clam,  278 

Pacific  crab,  292 

Painted  tortoise,  326 

Pangenesis,  338 

Panther,  169 

Parasites,  use  of,  to  control  insects, 

161 
Parasitic  bacteria,  221 
Parasitic  protozoa,  266 
Parasitic  worms,  107 
Parsnips,  105 
Passenger  pigeon,  36,  43,  44  ;   egg 

of,  43  ;  picture  of,  36 
Pasteur,  196,  209 
Pavement  ant,  156 
Peach,  94,  165 
Peach  yellows,  214,  215 
Peach-tree  borer,  156 
Pear,  94 

Pear  and  apple  blight,  212,  213,  216 
Pear  slug,  157 
Pear-blight  beetle,  155 
Pearl  fishing,  279,  280 


I 


INDEX 


375 


Pear-tree  borer,  155 

Pecau,  00 

Peeper,  31 « 

Pellagra,  113,  251 

Pennyroyal,  128 

Peonies,  86 

Pepper  biuli,  80 

Peppergra«s,  70,  71 

Perch,  306 

Perennial  crown«,  71 

PeriUjnitis,  234 

Periwinkle,  274 

llieasants,  40 

Phenol,  coefficient  of,  249 

Phloxes,  86 

Phoebe,  47  ;  food  of,  25 

Phosphates,  223 

Phosphorus,  96,  98,  99,  100,  101; 
used  for  poisoning  rats,  181 

Pickerel  frog,  315,  316,  319 

Pied-billed  grebe,  38 

Pig,  201  ;  as  host  for  trichina  wonn, 
267  ;  itch  mites  of,  166  ;  tapeworm 
of,  263 

Pigeon,  35,  36,  42;  killed  by  rats, 
174;  kinds  of:  band-tailed  pigeon, 
43 ;  passenger  pigeon,  43 ;  red- 
billed  pige^jn,  43  ;  Viosca's  pigeon, 
43 

Pigeon  grass,  70 

Pigeon  hawk,  45 

Pigweed,  09,  70 

Pimples,  248 

Pine,  59,  83,  84 ;  white  pine,  study 
of,  4,  5,  0 

Pintail,  39 

Pinworrn,  266 

Piroplasmas,  257,  268 

Pitch  pine,  59 

Plague,  236 

Plankton,  219 

Plant  food,  essential  elements  of,  99  ; 
losses  in,  due  to  cropping,  102 


Plant  lice,  153,  150,  104  ;  fecundity 

of,  18 
J:*lant  problems,  07-76*;  conservation 

of  native  plants,.  67 
Plantain,  71 
Plover,  40 
Plum,  165 

Plymouth  Rock,  104 
Pneumococcus,  234 
Pneumonia,  121,  184,  232-236,  248, 

250,  251 
Poison  ash,  75 
Poison  elder,  75 
Poison  hemlock,  72,  75 
Poison  ivy,  74,  75 
Poison  laurel,  75 
Poison  oak,  74,  75 
Poison  root,  75 
Poison  snakeweed,  75 
Poison  sumac,  74,  75 
Poisonous  plants,  damage  from,  73 ; 

list  of,  75,  76 
Poisonous  snakes,  110,  327-329 
Pokeroot,  76 
Poke  weed,  75 
Poliomyelitis,  122 
Ponds,   as  balanced    aquaria,   304 ; 

possible  production  from.  307 
Poplar,  105 
Porpoises,  109 
Potash,  102,  223 
Potassium,  90,  98,  99,  100,  101 
Potat^j,  93,  97;    blight  or  scab  of, 

210,  215 
Potato  beetles,  42,  153 
Poultry,  103,  104 
Poultry  mite,  167 
Pout,  306 

'Prairie  chicken,  63 
Prawns,  287 
Proteans,  313 
Protein,  187,  189 
Protozoa,  266,  25Cf 


376 


CIVIC  BIOLOGY 


Puerperai  fever,  234 
Puff  balls,  189,  191,  203,  206 
Pulmonary  tu"berculosis,  249 
Purple  beech,  83 
Purple  cornflower,  73 
Purple  flnch,  49 
I'urple  niartin,  49 
Purslane,  69,  70 

Quack  grass,  72 

Rabbit,  169,  261 

Rabid  dogs,  110 

Rabies,  248,  256 

Ragweed,  70 

Railroad  worm,  156 

Rainbow  trout,  309 

Raspberry,  94 

Rat  snake,  326 

Rats,    30,    34,    44,    245,    267,  332; 

damage  from,   2,   174,   175,   176; 

extermination    of,    3,     177-184; 

fecundity  of,  2,   173;    poisoning 

of,    179,    180,    181  ;    problem   of, 

173-185;    trapping  of,   177,   178, 

179,  182,  184,  185 
Rattlebox,  76 

Rattlesnake,  253,  322,  327,  328 
Red  ant,  155 
Red  buckeye,  75 
Red  cedar,  59 
Red  gum,  59 
Red  mite,  129 
Red  pepper,  73 
Red  pine,  59 
Red  spider,  163,  164 
Red-backed  salamander,  316  , 
Red-eyed  vireo,  50 
Red-headed  woodpecker,  4(> 
lied-lnnuped   apple-tree  caterpilhii', 

15(5 
Red-legged  locust,  15(5 
Red-shouldered  hawk,  44,  45 


Redstart,  50 
Red-tailed  hawk,  45 
Red-winged  blackbird,  48 
Reptiles,  321-329  ;  products  of,  321, 

323 
Rheumatism,  233,  234,  236 
Rhinitis,  234,  235 
Rhizopus,  198 
Rhododendron,  76 
Roaches,  245.    See  also  Cockroaches 
Robin,  51 
Rock  bass,  306 
Rock  pine,  59 
Rocky  Mountain  spotted-fever  tick, 

167 
Rodents,  326 
Root  gall,  212 
Root  knot,  265 
Root  rot,  211,  212 
Root  tubercles,  188 
Bosa  rugosa,  89,  97 
Rose,  86,  94,  97 
Rose  chafer,  156 
Rose  slug,  157 
Rose-breasted  grosbeak,  49 
Round-headed  apple-tree;  borer,  155 
Roundworms,  264,  265,  266 
Ruby-crowned  kinglet,  51 
Ruby-throated  hunnning  bird,  47 
Ruffed  grouse,  41,  42,  52,  53 
Rum  cherry,  75 
Rust,  186,  207,  210,  212 

Sable,  171 

Saccharomycetes,  191 
Salamanders,  313,  316,  319,  320,  325 ; 

enemies  of  mosquitoes,  131 
Salmon,  309,  310,  311 
San  Jos^  scale,  20,  (59,  152,  156,  158, 

332;  fecundity  of,  18 
Sand  flies,  113 
Saprolegnia,  305 
Saprophytic  bacteria,  221 


TNl^EX 


377 


Sapsucker,  46 

Sawflies,  153 

Sayornis  phoebe,  47 

Scab,  on  apple,  212  ;  on  potato,  210 

Scale  insects,  153,  156 

Scallops,  273,  274,  277 

Scarletfever,  177,  232,  233,  236,239, 
243,  245,  246,  247,  251,  256 

Scarlet  tanager,  25,  49 

Schick  reaction,  251 

Scientific  organizations,  journals  of, 
352,  353,  354 

Scorpion,  163,  164 

Screech  owl,  45 

Screens,  cost  of,  20 

Screw-worm  fly,  113,  157 

Scrub  pine,  59 

Scurvy  scale,  156 

Sea  mussels,  271,  272,  273,  275;  pic- 
ture of  beds  of,  270 

Seed,  188 

Selection  and  survival  of  the  fittest, 
330 

Seneca  snakeroot,  73 

Septicaemia,  234 

Serum,  248;  antitoxic  sera  for 
snake  poisons  (antivenins),  329  ; 
Flexner's  anti meningitis.  111  ;  re- 
sistance of,  249 

Shad,  296,  309,  310,  311 

Sliagbark  hickory,  82 

Sharp-shinned  hawk,  45 

Sheep,  257,  263;  itch  mite  of,  166; 
liver  fluke  in,  261 

Sheep  botfly,  157 

Sheep  laurel,  75 

Sheep-scab  mite,  163,  166 

Shepherd's-purse,  70,  71 

Shetland  ponies,  333 

Shore  bird,  40 

Short-leaf  pine,  59 

Shrikes,  30,  34,  50 

Shrubs,  84,  86 


Silicon,  98 

Silver  fox,  172 

Sirens,  313,  314 

Sistrurus,  327 

Skink,  325 

Skunk,  169,  256 

Sleeping  sickness,  236 

Slug,  currant,  157;  pear,  157  ;  rose, 
157 

Slugs,  282,  283,  315;  eaten  by  box 
tortoise,  325 

Small  laurel,  75 

Smallpox,  107,  211,  233,  236,  237, 
247,  251,  256  ;  control  of,  by  vacci- 
nation, 258,  259 

Smartweed,  70 

Smuts,  186,  207,  210 ;  on  corn,  213, 
216  ;  on  oats,  212 

Snails,  274,  283 

Snake  venom,  treatment  of,  329 

Snakes,  40,  321,  323;  number  of 
species  of,  326 ;  poisonous,  110, 
327-328 

Snakeweed,  75 

Snapping  terrapin,  324 

Sneezeweed,  76 

Snowball,  97 

Snow-on-the-mountain,  76 

Society  for  the  Protection  of  Native 
Plants,  67 

Sodium,  98 

Sodium  chloride,  249 

Sodium  hypochlorite,  249 

Soft,  or  long-necked,  clam,  276,  278 

Soft-shelled  terrapin,  325 

Soil,  effects  of  washing  on,  57  ;  ele- 
ments in,  99  ;  fertility  of,  91,  98  ; 
loss  of  fertility  of,  55,  102 

Song  birds  killed  by  rats,  174 

Song  sparrow,  49 

Sonoran  coral  snake,  328 

Sorghum,  197 

Sourwood,  59 


378 


CIVIC  BIOLOGY 


Southern  clothes  moth,  154 

Sow  bug,  317 

Sparrow,  34,  45,  47,  49,  50,  182 

Sparrow  hawk,  45 

Sphinx  moth,  155,  156 

Spidei-s,  46,  51,  163-168,  315 

Spinal  meningitis,  107,  110 

Spirilla,  218 

Spirits  of  camphor,  128 

Spitzenburg  apple,  334 

Spoonwood,  75 

Spotted  cowbane,  75 

Spotted  fever,  233,  236,  256 

Spotted  parsley,  75 

Spotted  salamander,  316 

Spotted  sandpiper,  40 

Spotted  terrapin,  325 

SpiTice  pine,  59 

Spruces,  58,  83 

Squash  bug,  152,  156 

Squids,  273,  274 

Squirrel,  261 

Stable  fly,  20, 113,  121, 122, 154,  236  ; 

life  history  of,  121 
Stable-window  fly  trap,  108,  109 
Staggerbush,  76 
Staggerweed,  76 
Staphylococci,  234 
Stegomyia  fasciata,  258 
Stewart's  disease,  215 
Sticktights,  69 
Stinkhorns,  204 
Stinking  smut,  213 
Stinkweed,  75 
Stinkwort,  75 
Stork,  39 

Strains,  pure-bred  selected,  96,  97 
Strawberry,  94  ;  enemies  of,  156 
Streptococcus,  234 
Striped  cucumber  beetle,  156 
Strychnia  sulphate,  181 
Strychnine  used  for  poisoning  rats, 

180,  181 


Sugar,  danger  from  gorging  with, 
344 

Sugar,  or  rock,  maple,  82 

Sugar  pine,  59 

Sulphate  of  copper,  71 

Sulphur,  98,  99 

Sulphur  ointment,  165 

Sumac,  74,  75,  86 

Summer  cholera.  See  Summer  com- 
plaint 

Summer  complaint,  107,  110,  121 

Sunfish,  306 

Sunflower,  86 

Surra,  259 

Swallows,  49,  129 

Swamp  hellebore,  76 

Swamp  sumac,  75 

Swan,  38,  42 

Swatter,  119 

Sweet  peas,  86 

Swine,  174 

Sycamore,  59 

Symbiotic  bacteria,  221 

Syphilis,  107 

Syrphus  flies,  112 

Tachina  flies,  112 

Tadpoles,  314-318 

Tamarack,  59 

Tanagers,  49 

Tansy,  72 

Tapestry  moths,  154 

Tapeworm,  107,  254,  260,  262-264 ; 

of  dogs,  264;    of  fishes,  264;   of 

man,  261 
Tarantulas,  164 
Tea,  344 
Teal,  306 
Teasel,  71 

Tent  caterpillar,  155 
Termites,  155 
Terns,  38 
Terrapins,  321,  323,  324,  325 


INDEX 


379 


Tetanus,  248 

Texas  fever,  97,  163,  167,  168,  236, 
267 

Thorn  apple,  75 

Thrashers,  50 

Threadworms,  255,  264 

Three-leaved  ivy,  75 

Thrushes,  51 

Thunderwood,  75 

Ticks,  163,  164,  165,  236,  255  ;  cattle 
tick,  167,  168,  257  ;  dog,  or  wood, 
tick,  168 ;  Rocky  Mountain,  or 
spotted-fever,  tick,  167 ;  species 
of,  168 

Titmice,  51 

Toads,  306,  312-320;  commercial 
value  of,  317;  eggs  and  tadpoles, 
314-316,  318;  food  and  feeding 
tests,  312,  315,  317 

Tobacco  as  an  insecticide,  114,  343 

Tomato,  94 

Tonsillitis,  233,  234, 235, 243, 245,  251 

Tools,  13,  14 

Toothache,  233 

Tortoises,  321,  324,  325 

Towhee,  49 

Trailing  arbutus,  67 

Tree  frogs,  313,  314-,  316,  319,  320 

Tree  sparrows,  34,  49 

Tree  swallows,  49 

Trees,  characters  of,  82 ;  hard  woods, 
59  ;  light  demanders,  59 ;  planting 
of,  61  ;  relation  of,  to  landscaping, 
81,  83,84 ;  shadebearers,  59 ;  study 
of,  59,  60 

Trematodes,  260 

Trichina,  175,  266,  267,  268 

Trichinosis,  264,  266 

Trout,  309 

Trumpeter  swan,  39 

Truth,  fake  sources  of,  347 

Trypanosomes,  259,  260 

Tsetse  flies,  236,  259,  260 


Tuberculosis,  107, 110,  121,  232,  234, 
235,  236,  245,  250,  251,  252,  256 ; 
avian,  233  ;  bovine,  110,  233 ;  pul- 
monary, 249 

Tuberoses,  86 

Tubers,  71,  307 

Turkeys  killed  by  rats,  174 

Turpentine  a  remedy  for  dog  tick, 
168 

Turtles,  131,  321,  323,  325 

Typhlitis,  234 

Typhoid,  20,  110,  118,  121,  177,  232, 
234,  235,  236,  242,  243,  245,  248, 
251  ;  epidemic  of,  241  ;  relation  of 
dirty  hands  to,  250 

Typhoid  fly,  107,  112  ;  life  history 
of,  113.    See  also  House  fly 

Typhoid  Mary,  242 

Typhus  fever,  236,  256 

Uncinariasis,  268 

Vaccination,  258 

Vaccines,  248 

Van  Fleet  rose,  97 

Variation,  330,  338  ;  law  of,  333 

Vedalia  beetle,  20 

Vegetables,  pests  of,  156 

Venomous  snakes,  324 

Vermin,  245 

Vinegar  eels,  265 

Vines,  87  ;  relation  of,  to  landscape 

gardening,  87,  88,  89 
Viosca's  pigeon,  43 
Viper,  327 
Vireos,  48,  50 
Virginia  scrub  pine,  59 
Vivaria,  10,  131 

Walking  sticks,  153 
Walnut.    See  Black  walnut 
Wapata,  307 
Warblers,  48,  50 


380 


CIVIC  BIOLOGY 


Warbling  vireo,  50 

Wasps,  153 

Water  beetles,  larva?  of,  131 

Water  bugs,  153 

Water  cress,  306,  307 

Water  hemlock,  73,  75 

Water  lilies,  306,  307 

Water  snakes,  326 

Waterfowl,  38,  39,  40,  45,  324 

Waxwings,  50 

Weasels,  169 

Weeds,  67-76 ;  adaptability  of,  70 ; 

classes  of,  70,  71 ;   damage  from, 

68  ;  destruction  and  control  of,  34, 

69,  71 ;  medicinal,  71,  72 
Weeping  willow,  84 
Weevils,  155,  156,  317 
Western  little-neck  clam,  278 
Western  prairie  chicken,  42 
Whale,  169 
Wheat,  93,  94,  95,  97 
Whippoorwill,  47,  129 
Whistling  swan,  39 
White  ants,  153,  155 
White  ash,  82 
White  cedar,  59 
White  diarrhea  of  chicks,  233 
White  elm,  59 
White  hellebore,  76 
White  man's  plant,  75 
White  pine,  59,  84  ;  type  for  study, 

4,  5,  6 
White-breasted  nuthatch,  51 
Whitefish,  309 

White-marked  tussock  moth,  156 
White-throated  sparrow,  49 
Whooping  cough,  232,  234,  247 
Wicky,  75 
Widal  reaction,  251 
Wild  boar,  263 
Wild  carrot,  71 
Wild  cat,  169 
Wild  celery,  307 


Wild  cherry,  75 

Wild  duck,  53,  325 

Wild  onion,  71 

Wild  rice,  307 

Wild  rose,  86 

Wild  sago,  307 

Wild  trout,  305 

Wild  turkey,  42,  53 

Willow,  59,  307 

Wilson  snipe,  40 

Wilson's  thrush,  51 

Wilt  disease,  212  ;  bacterial  blight, 

215  ;  stem  blight,  216 
Window  flytrap,  108,  109 
Wode-whistle,  75 
Wolf,  169,  256  ;  itch  mite  of,  166 
Wolfsbane,  76 
Wolf  s-milk,  76 
Wolverine,  169 
Wood  duck,  39,  40,  306,  307 
Wood  frog,  315,  316,  319 
Wood  laurel,  75 
Wood  pewee,  food  of,  24,  47 
Wood  thrush,  51 
Wood  ticks,  165,  168 
AVoodcock,  40 
Woodpecker,  7,  46 
Woolly  apple  louse,  156 
Woolly  loco  weed,  76 
Worms,  51,  315 
Wormseed,  69 
AVrens,  50 

Yeara,  75 

Yeast,  186,  189-197  ;  a  cause  of  dis- 
ease, 197  ;  description  of,  191, 192  ; 
distribution  of,  192  ;  pure  culture 
of,  195  ;  uses  of,  194 

Yellow  fever,  20,  123,  124,  126,  134, 
233,  236,  240,  253,  254,  256,  258 

Yellow  perch,  309  ;  topography  of, 
298 

Yellow  pine,  59 


INDEX  381 

Yellow  poplar,  61)  Yellow-throated  vireo,  50 
Yellow  warbler,  50 

Yellow  woolly  bear,  155  Zero  family,  345 

Yellow-billed  cuckoo,  40  Zinnias,  86 

Yellow-fever  mosquito,  124,  125  Zoological  parks,  171 


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